DE2202518A1 - Ara-cytidine O-ester and process for their preparation - Google Patents

Description

It REAL LAWYERS

D2. hi? .. Γ: · L-CMEM. WALTER ATi

. : ■: .- ;. ".VOLFP

Jan. 19, 1372

623 Γ-3. I. '.

Our no. 17 587

The Upjohn Company Kalamazoo, Mich., V.St, A.

O-ester of ara- cytidine and process for their preparation

The invention relates to 2'-0-, 3 ^f -0-, 2 ', 3'-di-O-, 2', 5'-di-O- and 3 ¹ , 5'-di-0-esters of ara- cytidine and process for its preparation. The new 2'-O-esters (I) and 2 ', 5'-di-0-esters (II) have the general formula

OH

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I, II

ίη the Y

(1) RC- means, where R is an aliphatic radical with 1 bit 20 carbon atoms, an aromatic radical with 6 to 10 carbon atoms, a hydrocarbon radical with 7 up to 20 carbon atoms of the cage type, a monocyclic aliphatic radical with 4 to 10 carbon atoms, an araliphatic radical with 7 to 12 carbon atoms or a monocyclic heterocyclic Radical with 4 to 10 carbon atoms, and the radicals mentioned by halogen atoms, hydroxy, carboxy, Nitro, alkoxy or mercapto groups can be substituted, or

(2) R ¹ OC-, where R »is an aliphatic radical with 1 to 20 carbon atoms, an aromatic radical with 6 to 10 carbon atoms or an araliphatic radical with 7 to 12 carbon atoms,

and Z has the same meaning as Y or is hydrogen.

The new 3 ^f -0-esters (III) and 3 ', 5'-di-0-esters (IV) have the general formula

ZOCH

III, IV

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in which Z and Y have the meaning given above.

The new 2 ' _f 3'-di-O-esters (V) have the general formula

in which Y has the meaning given above.

The invention also encompasses the pharmaceutically acceptable acid addition salts of the above esters.

The compounds according to the invention are orally active, immune-suppressing and anti-neoplastic agents with depot action which have the characteristic properties of the anti-leukemic compound ara- cytidine.

In the above formulas I to V, the aliphatic and araliphatic radicals can be straight-chain or branched and also saturated or be unsaturated.

Representative acyl (RC) groups are:

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The acetyl, pivaloyl, isobutyryl, octanoyl (caproyl), palmityl, stearyl, oleyl, ß-chloropivaloyl, £ -nitrobenzoyl, 2-toluoyl, benzoyl, 2,6-dimethylbenzoyl, 2,4,6-trimethylbenzoyl, 1-fluorene carbonyl, 9-fluorene carbonyl, 1-naphthoyl, 1-indolecarbonyl, p-anisoyl, 3 »4,5-trimethoxybenzoyl, p-toluoyl, 1-norbornancarbonyl -, exo - or exo / endo mixtures of 2-norbornane carbonyl, 7-norbornane carbonyl, 2-adamantane carbonyl, 1-adamantane acetyl, cC-chloro-3,5,7-trimethyl-i-adamantane acetyl, pentacyclo [4.2 .0.0 '. O. '.0''J-octanecarbonyl (cuban carbonyl), cyclobutanecarbonyl, cyclopentanecarbonyl, cyclohexanecarbonyl, picolinyl, tetrahydrofuroyl (tetrahydropyromuconyl), 1O-xanthan carbonyl, nicotinyl, 6-methoxy-4-quinoline carbonyl (quinynyl-4-quinoline carbonyl) ) -, 4-cinnoline carbonyl, 2-thiophenecarbonyl, 4-thionaphthenacetyl, 2-furoyl, 5-brora-2-furoyl, cumaryl, coumarin-3-carbonyl, isonicotinoyl, 2-quinuclidine carbonyl, 3-quinuclidine carbonyl, 4-quinuclidine carbonyl, N-trichloroethoxycarbonyl-2-pyrrolecarbonyl, N-trichloroethoxycarbonyl-2-indole carbonyl, N-trichloroethoxycarbonyl-3-indole carbonyl, hydroxybenzpyl, 3-propyl hygroyl, , Hemiglutamyl, hemiglutaryl, hemi- (3 »3-dimethyl) -glutaryl, hemiitakonyl, hemiaconityl and the levulinyl groups as well as those in which R is the radicals

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CH (Cl) -

/ /

or

means.

The new esters according to the invention are prepared by novel acylation, ie esterification of new, suitably protected ara- cytidine intermediates.

An important class of these esters is obtained by acylation with an acyl halide or anhydride of an aliphatic one Acids with 1 to 18 carbon atoms, such as acetyl chloride or anhydride, isobutyryl bromide or anhydride, caproyl chloride or anhydride, palmityl chloride or anhydride, stearyl chloride or anhydride, lauryl chloride or anhydride, Oleyl chloride or anhydride, myristic acid chloride or anhydride or with their isomers.

In another important class of these esters, the acyl radical RC- comes from an aliphatic dicarboxylic acid 3 to 8 carbon atoms, such as glutaric acid, a 3,3-dialkylglutaric acid, succinic acid, itaconic acid or fumaric acid, the acylating agent being the corresponding Acid anhydride is used.

If the acyl radical bound to the 3-position oxygen atom of the ara-cytidine has the formula R ¹ OC-, then acylie-

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A compound of the formula R ¹ OC-Cl is used, the acylation being carried out using known methods for the preparation of carbonate esters on new protected ara-cytidine intermediates. In this case, R ^{1 is} an aliphatic radical having 1 to 20 carbon atoms, an aromatic radical having 6 to 10 carbon atoms or an aromatic radical having 7 to 12 carbon atoms. Representative acylating agents are methyl chloroformate, ethyl chloroformate, butyl chloroformate, carbobenzoxychloride, octanoyl chloroformate, palmityl chloroformate, phenyl chloroformate.

The processes for preparing the new esters are described below.

Procedure A

2'-0-, 3'-0- and 2 ", 3 · -Di-0-esterification process, where Y is RC-.

The compounds of the general formulas

HIGH

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HIGH

III

HIGH,

in which R has the meaning given above, are prepared by

(1) a compound of the general formula

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VI

with a Trihalogenäthoxycarbonylhalogenid of the formula

CX ₅ CH ₂ OCX

in which X is chlorine or bromine, is converted into a compound of the general formula

O ti NH-C-OCH ₂ CX,

VII

in which X has the meaning given above;

(2) the compound obtained to compounds of the general Formulas

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NH-C-OCH ₉ CX I.

VIII

II NH-C-OCH ₂ CX ₃

IX

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II NH-C-OCH ₂ CX ₃

aoylated, in which X and R have the meaning given above to have;

(3) separating the acylation products from one another and

(4) the 5 * -0- and N -position hydrolyzed before one the compounds of the general formulas I, III and V are obtained.

Levels (3) and (4) can also be swapped.

The starting compound for stage (1), 5'-O-trityl ara cytidine (VI) is prepared according to Example 6 of US Pat. No. 3,284,440.

Includes in detail

(1) the first stage of process A the implementation approximately Equimolar amounts of the starting compound protected in the 5'-position, 5 -O-trityl-ara-cytidine (VI), and of the trihaloethoxycarbonyl halide, e.g. trichloroethoxycarbonyl chloride or tribromoethoxycarbonyl chloride, in a solution

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medium (eg dry pyridine) at low or moderate temperature to the corresponding N -Trihalogenäthoxycarbonyl-5'-O-trityl-ara-cytidine (VII), in which both the 5 ^f -O- and the N -position against dii tion in the Level (2) is protected.

0- as well as the N -position against the subsequent acylic

(2) The next stage of the process comprises the acylation of the N -Trihalogenäthoxycarbonyl-5'-O-trityl-ara- cytidine (VII) to the corresponding acyl-N-trihalogenäthoxycarbonyl-5 '-O-trityl-ara-cytidines (VIII , IX and X). The reaction can easily be effected by reacting the compound of the formula VII in a solvent such as dry pyridine at low or moderate (room) temperature with the appropriate acylating agent. Numerous acylating agents, namely acid chlorides of carboxylic acids or anhydrides of carboxylic acids, for example acetic anhydride, propionic anhydride, acetyl chloride, pivaloyl chloride, palmityl chloride _? 3-benzoyl chloride, S-fluorene carbonyl chloride, p-anisoylchloyl chloride, id: - norbornane carbonyl chloride, cuban carbonyl chloride, cyclopentane carbonyl chloride, 10-xanthan carbonyl chloride, 5-bromo-2-furoyl chloride, 3-quinucl ± lncarbonyl chloride, succinic anhydride and other agents already described introduce the desired acyl group RC-.

The acid chlorides of carboxylic acids used as acylating agents can be prepared by conventional methods, for example by reacting the acid RCOOH (a) with SOCl ₂ , (b) with PCl ^ or (c) with POCl. Method (a) is suitable for most acids. For those who have the same boiling point as SOCl ₂ with a deviation of 5 to 10 ° C., method (c) is suitable.

In the acylation process described above, the acylation takes place at the 2 ^f -0-position and / or the 3 ^f -0-position

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lung. In general, monoacylation is promoted by using lower mole ratios of acylating agent to compound VII of from about 1.0 to about 1.5, and preferably 1.1. The di-acylation is promoted by using the acylating agent in a molar ratio of more than 2, namely from about 2.1 to about 3, preferably from about 2.3. The V _e rlauf esterification, by thin layer chromatography using silica gel and ethyl acetate, or other known thin-layer systems are being persecuted.

(3) The esterification products VIII, IX and X are separated from one another and by countercurrent distribution or chromatography separated from other products and excess reactants. Column chromatography on a suitable Carrier is preferred. The column typically contains silica gel as a support and is made with ethyl acetate-cyclohexane Solvent mixtures or similar mixtures which are suitable for the separation of the acylates, eluted. For palmityl esters, 20:80 or 5O: 5O mixtures are used from ethyl acetate and cyclohexane appropriate. The admixture of ethyl alcohol, e.g. a mixture of cyclohexane-ethyl acetate-ethanol a ratio of 5: 3: 1 is useful. Further solvent systems emerge from the examples. The specific acylation product can be determined from the fractions flowing out, e.g. by UV absorption will. In general, the acylation products move at the following rates: 2 ', 3 * -Di-O-esters fastest, 3'-0-ester slower and 2'-0-ester slowest, often only a little slower than the 3'-0 esters.

(4) In the last stage of the process, the simultaneous hydrolysis at the 5 ¹ - and N -position of the acylating

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th N -Trihalogenathoxycarbonyl-5 * -O-trityl-ara-cytidine (VIII, IX and X) to the corresponding acyl ara- cytidines (I, III or V). The hydrolysis is effected by mixing a compound of the formulas VIII, IX or X with zinc (preferably as dust) and acetic acid (e.g. 80 % glacial acetic acid and 20 % water) at moderate (room) temperature to steam bath temperature for a few to about 24 hours. The corresponding acyl- ara- cytidine (I, III or V) is obtained.

If desired, the separation steps (3) and the Hydrolysis stage (4) are exchanged for one another.

The compounds of formulas VIII, IX and X can also be converted into the corresponding acyl-ara-cytidines (I, III or V) in two steps, for example by first mixing the former with a dilute solution of trifluoroacetic acid in a solvent such as chloroform in order to remove only the 5 -O-trityl group, whereupon the protective group at the N position is removed from the obtained acyl-N ^ -trihalogenethoxycarbonyl-ara-cytidine, for example by heating with zinc in methanol under reflux, and the corresponding acyl ara- cytidine (I, III or V) obtained ri.rd. It is also possible to first remove the IP-trihalogen ethoxycarbonyl group by hydrolysis with zinc acetate and methanol and, from the 3'-O-acyl-5'-O-trityl-ara-cytidine obtained, the 5'-O-trityl group with a mixture split off from 80 % glacial acetic acid and 20 % water or with an approximately 1% solution of trifluoroacetic acid in chloroform.

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Method B 2'-0-, 3'-Og and 2 ', 3'-di-O-esterification, where YR ^{1 is} OC-

The compounds of the general formulas

HIGH

I '

HIGH,

III ^!

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. - 15 -

HIGH

V »

in which R ^{1 has} the meaning given above, are prepared by

(1) a compound of the formula

VI

OH

with a Trihalogenäthoxycarbonylhalogenid of the general formula

0
CX ₃ CH ₂ OCX

in which X is chlorine or bromine, to a compound of the general formula

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NHCOCH ₂ CX,

VII

converts, in which X has the meaning given above;

(2) the compound obtained with a compound of the general formula

0 η

R ¹ OCCl

in which R ^{1 has} the meaning given above, to compounds with the general formulas

OCH ₂ CX ₃

VIII

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COCH ₂ CX ₃

IX ¹

X '

OCOR

in which R ¹ and X have the meaning given above;

(3) separating the acylation products obtained from one another;

(4) from them the 5'-0-trityl group by hydrolysis to form the compounds of the general formulas

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NHCOCH ₈ CX ₃

HQ ₁ CHa-o

VIII "

HIGH ₂

IX "

OCOR

NHCOCH ₂ CX ₃

HIGH

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in which R ¹ and X have the meaning given above, removed and

(5) the compounds prepared in this way are hydrolyzed at the N position to ^{form the compounds of the general formulas IJ III 1 and V ».}

If desired, step (3) can follow steps (4) and (5).

In detail is

(1) the first stage of procedure B with the first stage of method A identical.

(2) The second stage of this process, that is, the acylation of the N-Trihalogenäthoxycarbonyl-5'-O-trityl-ara- cytidine (VII) to the corresponding acyl-N-trihalogenäthoxycarbonyl "51-O-trityl-ara-cytidines (VIII ', IX ¹ and X ¹ ) corresponds to step (2) of process A. However, the acyl radical has the formula R ¹ OC-, in which R ^{1 has} the meaning given above, and the acylating agent-ROCCL, The acylation is carried out according to known Process for the preparation of carbonate esters, for example a compound of the general formula VII with an acylating agent R ¹ OCCL (such as methyl chloroformate, ethyl chloroformate, propyl chloroformate, carbobenzoxychloride, octyl chloroformate, stearyl chloroformate, phenyl chloroformate or xylyl chloroformate) at a moderate (room) temperature Acyl-N trihalogenethoxycarbonyl-5'-O-trityl-ara-cytidines (VIII ', IX ¹ and X ¹ ) about 1.0 to about 1.5 moles, preferably about 1.1 moles, of acylating agents are used for the monoacylation et, for the di-acylation about 2.1 to about 3.0 moles per mole of compound VII, preferably about 2.3 moles. In the acylation process described above, the acylation is carried out as in step 2 of the

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driving A at the 2'-0-position and / or the 3'-O-position.

(3) In the third stage of this procedure, the acylation products separated from each other. One works in the same way as in the separation stage of process A.

However, this stage can also only be carried out after the protective groups are in the 5'-O and N positions removed in steps (4) and (5).

(4) The fourth step of this process consists in the hydrolysis at the 5'-0 position to remove the 5'-O-trityl group with formation of the corresponding acyl-N trihalogenethoxycarbonyl-ara-cytidines (VIII ", IX" or X " The hydrolysis is effected, for example, by treating the acyl-N -trihalogenethoxycarbonyl-5'-O-trityl- ara -cytidine (VIII ¹ , IX ¹ or X ') with a weak acid (e.g. acetic acid) at a moderate (room -) Temperatur converts to the corresponding acyl-N -trihalogenäthoxycarbonyl-ara-cytidinen (VIII ", IX" or X ").

(5) The last stage of the process consists in the hydrolysis to remove the protective trihalogenethoxycarbonyl group in the N position with the formation of the corresponding acyl-ara-cytidines (I ¹ , III ¹ and V ¹ ). The hydrolysis is achieved, for example, by heating (optionally under reflux) the compounds of the general formulas VIII ", IX" or X "in methanol with zinc, zinc acetate or zinc chloride.

Method C 2. ' 5'- and 3'5'-di-O-esterification, where Y and Z are RC-

The compounds of the general formulas

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RCOCH,

NH.

O H RCOCH,

HOy

II

IV

If

OCR

in which R has the meaning given above, are prepared by

(1) a compound of the general formula

(T ^

HIGH ₂

HO '

XIa

in which w ^ is an anion of a strong acid, to compounds the general formulas

RCOCH,

OCR

Ha

IVa

in which R and w ^{w have} the meaning given above, acylated;

(2) neutralized to remove the proton in the N position of the compound of general formula V thus prepared and

(3) separates the acylation products.

Includes lm individual

(1) The first stage of process C is the acylation of an acid addition salt (XIa) of the known ara-cytidine, such as the hydrochloride, hydrobromide, hydroiodide, sulfate, phosphate or benzenesulfonate, with the formation of the corresponding diacyl- ara -cytidine salts (Ha and IVa). This reaction is easily achieved by mixing a compound of the formula XIa in a solvent such as dimethylacetamide, diethylformamide or propionamide at moderate (room) temperature with the corresponding acylating agent. Numerous acylating agents can be used, ie anhydrides or chlorides of carboxylic acids, for example acetic anhydride, butyric anhydride, valerlanic anhydride, adipic anhydride, succinic anhydride, cyclopentanecarbonylchloride, isopicDÜ / iylchloride, laciiikocinylchloride, laciiikocinyl chloride, xylouoylchloride, 2,4-toluylchloride, cylchlorophylchloride , 6-tri. Ethyittnzoyl chloride, etc. To achieve a Dl ~ i \ .cy ~ ;. . · EruTig das a £ C "^:; tlil <.ri · salt (XIa) a molar ratio / Ac; j \> lo? \ Pi & Mirtbvj. To the starting compound should be used in excess of the amount required for the muoacylation, Bas: The ratio should be in the range of about 2 to about 2.5 moles (preferably about 2.5 moles) of acylating agent, one mole of the N-position protected compound (XIa). A larger excess of acylating agent should be avoided to prevent the formation of the to keep 2 ^f , 3 *, 5 ^! -tri-O-acylated compound as low as possible.

(2) In the next step of the process, the neutralization of the acyl obtained in step (1) results in the removal of the proton in the N-position to give the corresponding diacyl ara- Cytidinsalze ara -Cytidinen (II and IV). Neutralization is achieved by mixing the compounds of formulas Ha and IVa with a mild alkaline agent such as an alkali metal bicarbonate, for example potassium bicarbonate

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or sodium bicarbonate, or an organic base, such as Pyridine causes. Because of the greater water solubility of the acid addition salts, however, it is also possible that the Compounds of the general formulas Ha and IVa are preferred as end products in certain cases.

(3) In the final step of the process, the desired di-O-acylates are prepared using those described above Methods, e.g., by column chromatography of each other and of the mono- and triacylates formed simultaneously as well as separated from the reactants and other products.

The 3'-0- (HI) and 3 ¹ , 5'-Di-O- (IV) ara-cytidine esters can also be made from 2,2 * -anhydro- ara -cytidine (XIIa)

HOH ₂ C

XIIa

or its acid addition salts (XIIb)

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HOH ₂ C

XIIb

OH

is "the anion of a strong acid, for example where w is the hydrochloric or sulfuric acid. 2.2'-anhydro-ara-cytidine (XIIa) and its acid addition salts (XIIb) can be prepared by the in J. Org. Chem. Vol. 32, p 1462 can be produced.

The use of 2.2 * -Anhydro- ara- cytidine in the synthesis of esters of the invention is advantageous because in this anhydro the hydroxyl group in ^{the 1-position} of the 2 dee ara -Cytidins already blocked and the esterification is not accessible. Contact with water or alcohol, especially in the presence of a base, leads to hydrolysis of the anhydrous bond and should be avoided during synthesis, purification of the products or isolation of the intermediates if such hydrolysis is undesirable.

When the 2,2'-anhydro-ara-cytidine is acylated in the non-protonated form XIIa. For example, by acylation of XIIa in pyridine, the N-imino ^{group tends to be acylated in addition to the 3 1} - and 5'-0H groups, so that the N, 3 "_0-, 5" -O-triacylate (XIII) is formed . This method (see method D, below) is nevertheless in the production of aromatic, e.g. benzoyl, 3 ^f , 5'-di- (0-acyl) ·

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ara-cytidine compounds useful when the IP acyl group can easily be removed selectively by hydrazinolysis.

Alternatively, and usually preferably, the 2,2'- anhydro-ara- cytidine is used in its N -protonated form (XIIb), ie as an acid addition salt (method Dg). The protonation blocks the undesired acylation on the 4-position nitrogen and is advantageous to avoid hydrazinolysis which becomes necessary or another selective acylation on the 4-position nitrogen compared to the use of a compound of the formula XIIa.

In derjerfindungsgemäßen synthesis of ara -Cytldinacylaten using anhydro-ara -Cytidinen (XIIa or XIIb) anhydro-ara-cytidine be acylated first. If desired, the anhydro-ara-cytidine acylates formed as intermediates can be isolated. Usually, however, the intermediates are not isolated and, for reasons of economy, the synthesis is carried out up to the hydrolysis stage.

When using anhydro-ara cytidine for the manufacture of 3'-O-esters (III) of ara-cytidine is for the acylation reaction, a compound in which the 5 x -O-position is protected in a suitable manner, for example, 5 ' -O-Trltyl-anhydroara-cytidine is used and the protective group in the 5'-O position is subsequently removed.

Method D ₁ 3 '»5'-Di-O-Esterification using

of 2,2'-anhydro-ara-cytidine (XIIa)

A compound of the general formula

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Y ¹ OCH,

IV »

OY

is atoms, an aromatic acyl group having 6 to 12 carbons in the Y ^1, is prepared by reacting

(1) a compound of the formula

HOH ₂ C

XIIa

with an acylating agent of the formula

Y ¹ OY * or Y ¹ X ₁ ,

in which Y * has the meaning given above and X .. is chlorine, bromine or iodine, to a compound of the general formula

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Y ¹ OH ₂ C

XIII

OY ¹

implements

(2) the acyl group on the 4-position nitrogen atom to form a compound of the general formula

Y ¹ OH ₂ C

XIV

in which Y ^{1 has} the meaning given above, selectively removed and

(3) the 2,2'-anhydrous bond is hydrolyzed to ^{form a compound of the general formula IV 1.}

In detail will

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(1) the acylation by reaction of the 2,2'-anhydro-ara-cytidine (XII) with a corresponding aromatic AcylteLogenide, e.g. an acyl chloride, bromide or iodide or the corresponding aromatic acyl anhydride in a suitable, usually carried out basic solvent which does not hydrolyze the 2,2 · anhydrous bond, e.g. in Triethylamine, tributylamine, dimethylaminoaniline or preferably in pyridine. The aromatic acyl chlorides are preferred as acylating agents, although others are also preferred Halides or acyl anhydrides can be used. Per mole of compound XIIa should be about 3 to about 4, preferably about 3.5 moles of acylating agent can be used. Usually the reaction goes well at room temperature but slightly elevated temperatures, e.g. about 55 ° C, can be used to accelerate the reaction will. The course of the reaction can be monitored using suitable methods, e.g. thin-layer chromatography will. After the reaction, the solvent is evaporated off. If desired, it can be formed as an intermediate Triacyl compound XIII can be isolated by recrystallization, column chromatography or other known methods.

(2) The crude or purified intermediate XIII is then reacted with a reagent which has the acyl group on 4-position nitrogen atom is able to remove, "e.g. with Hydrazine in pyridine-acetic acid (4s1) at room temperature. This procedure is particularly useful for removal aromatic acyl groups, e.g. from benzoyl groups. In order to protect the anhydrous bond, anhydrous conditions must be used can be applied. If desired, intermediate XIV can be isolated. Usually, however carried out the next stage without prior isolation.

(3) The anhydrous bond is hydrolyzed by reaction with water, preferably in the presence of basic catalysts. The 3'.5'-di- (O-acyl) - ara -cytidine ester obtained is using known methods, for example by chromium »

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purified matography or recrystallization.

The 2,2 · anhydrous bond can also be carried out prior to the removal of the Acyl group on the 4-position nitrogen atom can be hydrolyzed, e.g. by reaction with water or an alcohol and neutralization. In this case, the intermediate, N ^, 3 * -O, 5'-O-triacylate of the formula

XV

OY ¹

e.g. isolated by chromatography or recrystallization.

Method D ₂ 3 ', 5' -di-O-esterification using ------- _of protonated 2,2 '-Anhydro- ara cytidine

(XIIb)

A compound of the general formula

YOCH

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IV

in which Y has the meaning given above, is thereby made that one

(!) a compound of the general formula

HOHoC

XIIb

OH

in which w ^ is the anion of a strong acid, with a Acylating agents of the formula

YOY or YX ₁

in which Y and X ^ have the meaning given above a compound of the general formula

NH ₂ 0 w ©

YOH ₂ C

XVI

converts, in the Y and w ^ the meaning given above have and

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(2) the 2,2'-anhydro link to form a compound of the general formula IV or its acid addition salt hydrolyzed.

In detail will

(1) in the acylation step is the protonated form of the 2,2'-anhydro-ara- Cytldins XIIb in a solvent which is able to keep the anhydro ara -Cytidlnverbindung in protonated form, for example in a non-basic solvent such as dimethylformamide or Dimethylacetamide reacted with a corresponding acyl halide or anhydride. About 2.1 to about 3.0 moles, preferably about 2.3 moles of acylating agent should be used per mole of compound XIIb. The reaction mixture can be heated, for example to about 55 ° C., and the course of the reaction can be monitored, for example by thin layer chromatography.

If desired, the intermediate 3 ^1, 5'-di- (0-acyl) · anhydro ara- cytidine (XVI) or the free amine base using known methods, can be isolated by crystallization or chromatography for example. However, compound XVI need not be isolated.

(2) The hydrolysis is carried out by reaction with water or alcohol and is easy to proceed especially when it is is catalyzed by a base, e.g. by neutralizing to remove the proton on the 4-position nitrogen or makes it slightly alkaline.

The product can be purified using known methods such as crystallization or chromatography. For example, the dipalmitate is easily identified by chromatography on silica gel using methyl ethyl ketone-acetone-water separated in a ratio of 72: 20: 8, the individual compounds in the eluate being separated by UV

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sorption and identified by thin layer chromatography.

Method E 3 ^! -O-esterification using protonated 2,2'-anhydro- ara- cytidine (XIIb)

A compound of the general formula

HIGH

III

in which Y has the meaning given above, is produced by

(1) a compound of the general formula

HIGH

XIIb

)H

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in which w ^ is the anion of a strong acid, with a Triphenylmethyl halide to a compound of the general formula

XVII

Q
converts, in which w has the meaning given above;

(2) the compound obtained with an acylating agent of the general formula

YX ₁ or YOY

in which Y has the meaning given above and X _{1 is} chlorine, bromine or iodine, into a compound of the general formula

XVIII

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transferred, in the Y and w ^ the meaning given above to have,

(3) the compound obtained to form a compound of the general formula

HIGH,

XIX

in which Y and w have the meaning given above the 5'-O position hydrolyzed and

(4) the compound so produced to form a
Compound of the general formula III hydrolyzed.

To be more precise

(1) approximately equimolar amounts of triphenylmethyl halide, the also known as trityl halide, reacted with an acid addition salt of 2,2'-anhydro-ara-cytidine (XIIb). The reaction can be carried out at room temperature for an extended period of about a week. she can also take place at elevated temperatures of 50 to 70 ° C. It can either be triphenylmethyl chloride, bromide or iodide be used. Although pyridine is an excellent solvent for this reaction, you can too other solvents such as tributylamine or N, N-dimethylaniline can be used. After completion of the implementation the solvent is removed.

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(2) In the second stage, the acid addition salt of 5'-O-trityl-ara-cytidine obtained is reacted with the selected acylating agent. It is important that at this stage the ΙΓ-imino group of the cytosine portion of the molecule is kept in the protonated state as the imine salt of a strong acid such as hydrochloric or sulfuric acid. Dimethylformamide and dimethyl acetamide show good solubility for these compounds and are therefore suitable as solvents. Usually, the amount of solvent used need not be sufficient to completely dissolve these compounds, since as the reaction proceeds, solution will occur and the final reaction mixture will be homogeneous. When using an acylating agent with the formula ΎΧ., Ie an acyl halide, X ₁ can be either chlorine, bromine or iodine. Acid anhydrides (YOY) can also be used. About 1.0 to about 1.5 moles, preferably about 1.1 moles, of acylating agent should be used per mole of compound XVII. The acylation usually proceeds easiest at slightly elevated temperatures of, for example, 40 to 50 ° C. After removing the solvent in vacuo using a high vacuum pump and a water bath at about 45 ° C., the desired intermediate can be purified by chromatography on silica gel.

(3) In the third stage, the protective trityl group is removed. This selective removal is most conveniently accomplished with an acidic reagent made up of about 80 parts glacial acetic acid and 20 parts water. Lower proportions of water can also be used, but higher proportions of water can lead to the insolubility of the starting material in the reaction mixture, so that a heterogeneous and undesirable reaction occurs. The 5'-0-trityl group can also be removed with a mixture of chloroform and about 1 to 3 % trifluoroacetic acid. Although both reagents are used at room temperature or below

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can, it is also possible to carry out the reaction at slightly elevated temperatures. This is particularly true when using the aqueous acetic acid, although in this case sometimes undesirable at elevated temperatures Side reactions occur.

The 2.2 x -Anhydro-3'-O-ester of ara cytidine (XIX) formed as intermediates show good stability in aqueous solution, as long as the ^4! -Imino group remains protonated. In a neutral or weakly alkaline solution, the anhydrous ring is easily hydrolyzed and the 3'-0-esters of ara- cytidine are formed. The anhydroesters XIX can be isolated using known methods, for example by chromatography or evaporation and crystallization.

(4) In the last step, the 2,2'-anhydrous bond is hydrolyzed by neutralizing or making it slightly alkaline, whereupon the 3'-O-acyl- ara- cytidine esters III are formed.

The use of 2,2 '-Anhydro-ara-cytidine (XII) in the synthesis of 3'-0-ester (III) of the ara-cytidine is described in Example 8. FIG.

All of the compounds according to the invention of the general formulas I to V can be prepared from their reaction mixtures in a conventional manner Isolated in a manner such as, if a water-miscible solvent has been used, by pouring of the reaction mixture in water and separating off the resulting precipitate by filtering or extracting with water-immiscible solvents. Further purification of the products can also be carried out in a conventional manner Manner such as elution chromatography using an adsorption column and an appropriate one Solvents such as acetone, cyclohexane, chloroform,

2 0 9833/1221

Methanol, ethanol, ethyl acetate, ether, methylene chloride and hexane hydrocarbons (Skellysolve B) and mixtures and combinations of these solvents; also through gradual elution chromatography using a suitable mixed solvent such as methylene chloride-Skellysolve B, acetone-Skellysolve B and the like.

The water solubility of the monoesters and diesters according to the invention can be improved and their pharmaceutical applicability can thereby be broadened if they are converted into their salts with pharmaceutically suitable acids which have a pK value of about or less than 2. The strong mineral and organic acids are suitable for this, since ara- cytidine and the esters according to the invention are weak bases. Examples of strong acids are hydrochloric, sulfuric, phosphoric, glutaric, glutamic, tartaric, trihydroxybenzoic and formic acids. The salts are prepared by suspending the desired esters of ara- cytldine in a medium such as methanol and adding one equivalent of the desired acid in a suitable manner. The result is a solution of the acid addition salt, from which the salt can be precipitated by adding an appropriate medium such as diethyl ether. The salts can be purified by recrystallization from solvent mixtures such as methanol-ether. The hydrohalides can be obtained by simply not neutralizing the acylation mixture from the reaction with RCOCl before isolating the acylated product from the solvent.

The compounds of the general formulas according to the invention I to V are valuable agents that suppress immune reactions. They are therefore used in organ transplants Significance, also in diseases that are caused by autoimmune reactions, and in persistent over-

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220251a

sensitivity. With a superior therapeutic ratio, they also counteract abnormal cell formation and above all possess the anti-leukemic efficacy that is characteristic of ara-cytidine. They have a depot effect and are effective orally.

In addition to the properties characteristic of ara- cytidine, the compounds according to the invention have the advantage that they release the ara- cytidine over a longer period of time after administration. The modes of administration and dosages are the same as for ara- cytidine. For example, they can be administered orally or intramuscularly. They can also be administered intravenously, with intravenous drip infusions not being necessary due to the depot effect of the new compounds.

The compounds according to the invention also have antiphage Properties and capabilities when used in conjunction with a deaminase inhibitor have one to protect from contamination by a phagocyte threatened fermentation process.

The esters according to the invention have the same effects and can be used for the same purposes as the non-esterified compound, cytarabine or ara-cytidine, namely effectiveness against acute leukemia in both adults and children and against lymphosarcomas in adults, see US patent specification 3 444 294. Like ara- cytidine, the esters according to the invention can be in sterile injectable solutions, for example in cottonseed oil, peanut oil and sesame oil, or in dispersions or sterile non-aqueous solutions or in dispersions in water, aqueous saline solutions or dispersions for the preparation of sterile injectables Solutions or dispersions can be transferred as required. Such solutions are thereby created

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provided that the esters are incorporated into the solvent or dispersion medium together with suitable coating agents for the particles, surfactants, bactericides or fungicides, isotonic agents and the like. Powders can be obtained by freeze-drying a solution or dispersion prepared in this way. Unit dosage forms, for example in vials and ampoules, are also possible. The dosage depends on the age, weight, severity of the symptoms of the disease, the mode of administration and the frequency of administration and can be from 0.1 to 50 mg / kg. The total daily dose can be from about 3 to about 4000 mg, which can be administered all at once or in multiple times. The unit dosage form can contain the ester of the invention in an amount of from about 3 to about 1000 mg. This can be about 0.5 to 25 % w / v. make up the entire composition.

Due to the depot action of the esters according to the invention, unit dosages can be made up and intramuscularly administered in a total dose of from about 0.5 to about 10 g or more, or from about 10 to about 50 mg / kg or more will. The amount of ester can be varied up to the dosage that is found to be sufficient for a decrease and proved an apparent cure for leukemia. A dose of 50 mg / kg can be administered once a week or higher doses can be applied at longer intervals.

Either solid or liquid unit dosage forms can be prepared for oral administration. For the manufacture of solid compositions, such as tablets, becomes the main effective ingredient with conventional materials, such as talc, magnesium stearate, dicalcium phosphate, magnesium aluminum silicate, calcium sulfate, starch, lactose,

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Acacia, methyl cellulose and similar acting materials mixed as pharmaceutical diluents or carriers. The tablets can be used against the digestive juices protective coating or not. Wafers can be made in the same way like tablets, they differ only in the form and in the incorporation of sucrose or other sweet and sweet Flavors. In their simplest form, capsules are made like tablets by mixing the active Component of the composition with an inert pharmaceutical diluent and filling in the mixture made in hard gelatin capsules of suitable size. In another embodiment, capsules are thereby prepared by filling hard gelatin capsules with granules containing the active compound and with a Polymers are coated. Soft gelatin capsules are made by machine encapsulation of a slurry of the active compound in a suitable vegetable oil, light liquid petrolatum or other inert get oil.

Liquid unit dosage forms for oral administration such as syrups, elixirs and suspensions can also be used getting produced. The water soluble forms of the active compound can be used in conjunction with flavorings be dissolved in an aqueous vehicle. Suspensions can be made from the insoluble forms with a syrup as a carrier using suspending agents such as acacia, tragacanth, methyl cellulose and the like.

Preparation 1 IT ~ Trichlorethoxycarbonyl-5'-0-trityl-aracytldine (VII)

193.69 g (0.40 mol) of 5 -O-trityl-ara-cytidine (VI) (also referred to as 5 ^f -Q-triphenylmethy1- ara- cytldine, prepared according to Example 6 of US Pat. No. 3,284,440) will

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dissolved in 4 l of freshly distilled anhydrous pyridine. The solution is cooled to 3 ° C. and 84.4 g (0.40 mol> Trichloräthoxycarbonylchlorid treated. The mixture is then stirred at 3 ° C. for about 4 hours. Then you leave within Warm up to 25 ° C in about 18 hours. The pyridine is distilled off at about 40 ° C. in vacuo and the one obtained treated gummy residue with 1 l of methylene chloride. 23.7 g of a solid separate out and are filtered off will. Thin layer chromatography shows that this solid is the starting material. the Methylene chloride solution is washed three times with 0.1 η hydrochloric acid and once with saturated saline solution. After drying over sodium sulfate, the methylene chloride is allowed to slowly evaporate, whereupon crystals separate out. The crystals are filtered off, washed with cold methylene chloride and dried. 64.5 g are obtained the desired product (VII). Thin-layer chromatography of the methylene chloride mother liquors reveals spots, moving faster than the product and likely made up of compounds at the 2'-0 and 3'-0 Position are acylated. They are hydrolyzed by mixing the residue of the mother liquor with 1 l of tetrahydrofuran and treated 1 1 0.3 η sodium hydroxide solution. After 11/2 hours they are all in the thin-layer chromatogram faster moving spots disappeared. It is then acidified to pH 6.5 with concentrated hydrochloric acid and distilled the tetrahydrofuran in vacuo and the aqueous residue extracted ntt methylene chloride. The methylene chloride solution it is washed and dried as above, then the methylene chloride is allowed to evaporate again. It divorced turn off crystals. They are collected and washed to give 42.5 g of product. The mother liquors will continue evaporated and still give 45.5 g of material, this time to stick out of product and to the other half consists of starting material, such as thin-layer chromatography

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graphics showed. The 45.5 g are heated with 500 ml of acetone and the residue that remains is filtered off. It consists of 5'-O-trityl ara- cytidine (VI). The acetone mother liquors are evaporated to dryness and recrystallized from methylene chloride with slow evaporation. 19 g of product (VII) are obtained. The total yield is thus 126 g of N-trichloroethoxycarbonyl-5'-O-trityl-ara- cytidine (VII), or 48% of theory. An analytical sample is prepared by recrystallizing twice from methylene chloride.

Analysis; Calculated for C, ₁

C 56.30; H 4.27; Cl 16.11; N 6.36; found: C, 56.46; H 4.30; Cl 15.25; N 7.26

..C ₉ HcOH *,

UV spectrum LÄ ^D mu (£ χ 10 "^)] ι 232 (11.8), 296 (5.38). Max

IR spectrum (r, mineral oil): 3380, 3200, 3120 Sch, 1765, 1650, 1620, 1570, 1505, 1330, 1245, 1200, 1100, 1085, 1065, 810, 785, 770, 750, 740, 715 and 705.

Example 1 2 »-0- and 3 ^f -O-palmityl-ara-cytidine (I and III)

15 g (30.3 millimoles) of palmitic anhydride are added to a solution of 19.8 g (30 millimoles) of the in-trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (VII) prepared as above in 150 ml of anhydrous pyridine. The mixture is stirred for about 16 hours at room temperature, after which a clear solution is obtained. The clear reaction mixture is examined by thin layer chromatography using silica gel and ethyl acetate as the solvent system. In this system two products appear with the R _f values 0.89 and 0.75 along with some starting material (R _f = 0.26). A further 1.4 g (2.8 millimoles) of palmitic anhydride are added and the reaction is carried out for a further 24 hours at room temperature. It is then concentrated in vacuo. About 39.3 g of a syrupy product are obtained

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Residue. The syrup is dissolved in 500 ml of ether and washed with 300 ml of 1 # sodium bicarbonate solution (3 g of sodium bicarbonate correspond to 36 millimoles). The ether layer is washed three times with 70 ml of water each time, dried over 70 g of anhydrous sodium sulfate and again concentrated in vacuo. 34.9 g of a syrupy residue are obtained. This residue is again examined by thin-layer chromatography using a different solvent system (cyclohexane-ethyl acetate in a ratio of 1: 1). In this system there is a fast moving spot (R _f «0.78), a double spot (R _f = 0.39) that looks like two components have not been completely separated, and some starting compound (VII), R _f = 0.02, on.

The 34.8 g of the crude product are adsorbed on 2.5 kg of silica gel and eluted with ethyl acetate, collecting 200 ml fractions when the elution of the reaction products begins. Fractions 1 to 3 contain only 2'-0, 3 ^! -0 ~ Dipalmityl-N -trichloroethoxycarbonyl-5'-O-trityl- ara -cytidine (X) (R _f = 0.79, ethyl acetate - cyclohexane in the ratio 1: 1). Evaporation in vacuo gives 3.9 g of a syrupy residue. This residue can be further treated as described in Example 9 to give 2 ', 3'-di-O-palmityl-ara-cytidine (V).

Fractions 4 to 30 are identified by thin layer chromatography using the solvent system ethyl acetate - Cyclohexane in a ratio of 1: 1 examined and indicate a mixture of three components. The United On evaporation, fractions result in 17.5 g of a syrupy residue. There will be another chromatographic Purification using a column of 2.5 kg silica gel and ethyl acetate - cyclohexanone as the eluent carried out. After about 8 liters of this solvent

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If the mixture has passed the column, the elution of the products begins. At this point 100 ml of the fractions are collected. Fractions 1 to 60 contain about 7.67 g of 2 '"0, 3'-O-Dipalmityl-N ^ -trichloroethoxycarbonyl-5'-0- ara -cytidine (X). Ethyl acetate is then used for the elution and there are collected fractions 71 to 83. They consist mainly of a mixture of 2'-O-palmityl-N-trichloroethoxycarbonyl-5'-O-trityl ara -cytidine (VIII) and 3 ^f -O-palmityl-N-trichloroethoxycarbonyl-5 '-O-trityl-ara-cytidine (IX). Fractions 71 to 83 give on evaporation in vacuo about 7.05 g of a mixture of the two aforementioned compounds with a little 2'0.3'-O-dipalmityl-N ⁴ -trichloroethoxycarbonyl-5 «-0-trityl-ara-cytidine (X).

The fractions 71 to 83 are adsorbed on a column of 500 g of silica gel and eluted with a mixture of 20% ethyl acetate and 80 % cyclohexane. After a few liters of solvent have passed the column, some of the faster moving dipalmityl derivative is eluted and the eluate is collected in 25 ml fractions. The fractions 1 to 120 consist mainly of 2'-0,3 "0-dipalmityl-NH-trichloroethoxycarbonyl-5 ■ -O-trityl-ara- cytidine (X). Fractions 120-440 contain some Dipalmitylverbindung and a trace impurity. Fractions 540 to 555 are combined and give 2.31 g of the essentially pure 3'-O-palmityl-N-trichlorethoxycarbony1-5'-0-trityl-ara-cytidine (IX) (R _f = 0.65, solvent system : Ethyl acetate-cyclohexane in a ratio of 1: 1, silica gel plates). The fractions 667 to 685 from the same column are combined and give 0.668 g of 5'-0-trityl-NT-trichloroethoxycarbonyl-2'-O-palmityl-ara-cytidine ( VIII) with traces of the corresponding 3'-O-palmityl compound. The fractions 686 to 717 are combined and give 2.07 g of pure 5'-O-trityl-N-trichloroethoxycarbonyl-

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21-O-palmityl-ara-cytidine (VIII) (R _f «O, 62, solvent system: cyclohexane-ethyl acetate-95% ethanol in the ratio 5: 3: 1).

The total of 2.31 g of 3'-O-palmityl-N-trichloroethoxycarbonyl-51-O-trityl-ara-cytidine (IX) are dissolved in a mixture of 20 % water and 80 % glacial acetic acid, and 3 g of zinc dust are added. The mixture is stirred for about 16 hours at room temperature, then the zinc is filtered off. On thin-layer chromatography, the clear filtrate gives a single spot that turns yellow when it is sprayed with dilute sulfuric acid after heating. Since this material still contains the 5'-0-trityl substituent, the clear filtrate is heated on a steam bath for about 6 hours, whereupon the test with dilute sulfuric acid shows that the product no longer contains the trityl group. The clear reaction mixture is concentrated in vacuo and the remaining solid is purified by adsorption on 200 g of silica and elution with chloroform-methanol in a ratio of 98: 2 and then with methyl ethyl ketone-acetone-water in a ratio of 72: 20: 8. 20 30 ml fractions are collected. Fractions 2 to 16 are combined and concentrated in vacuo to a solid. The solid is recrystallized from methanol and then from acetone. 3 * -O-palmityl-ara-cytidine (III) with a melting point of 174 to 176 ° C. is obtained.

Analysis: Calculated for C25 ^H 43 ⁰ 6 ^N 3 ^J

C 62.3; H 9.0; N 8.7; found: C, 61.8; H 6.3; N, 8.1.

UV absorption spectrum: 215 mu (light shoulder), £ = 10,200; 230 mu (high shoulder), £ - 7,900; 272 uju, ί ■ 9 100.

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0.89 g of 5'-O-trityl-IP-trichlorethoxycarbonyl ^ «- O-palmityl ara- cytidine (VIII) are dissolved in 50 ml of a mixture of 20 % water and 80 % glacial acetic acid. Then 2 g of zinc dust are added and the mixture is stirred overnight at room temperature. Thin-layer chromatography shows that the 5 ^f -0-trityl and ir-trichloroethoxycarbonyl group (VIII) are completely hydrolyzed. The zinc dust is filtered off and the filtrate is concentrated to dryness in vacuo. The residue is dissolved in a mixture of methyl ethyl ketone-acetone-water in a ratio of 72: 20: 8, adsorbed on 200 g of silica gel and eluted with the same solvent system. As soon as the UV absorption indicates that material is being eluted from the column, the eluate is collected in 50 ml fractions. Fractions 8 to 14 contain the desired product. These fractions are combined, concentrated in vacuo and the solid residue is recrystallized from acetone. 125 mg of 2'-O-palmityl-ara-cytidine (II) with a melting point of 133 to 134 ° C. are obtained.

Analysis: Calculated for C ^ H ^ O ^ N ^ I ^ O

C 60.09; H 9.08; N 8.41; Found: C, 60.07; H 8.90; N 8.69

UV: 236 μm, { = 7,300.
270 ιημ, ί = 8 850.

Following the procedure of Example 1 using the following acylating agents

(1) acetic anhydride

(2) pivalyl chloride

(3) oleyl chloride

(4) nicotinyl chloride

(5) 1-naphthoyl chloride

(6) 1-Adamantanac ety! Chloride

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(7) cyclobutanecarboxylic anhydride

(8) Plcolinyl chloride

(9) trans -3-n-propylhygric acid chloride

(10) succinic anhydride

(11) 3,3-dimethylgutaric anhydride

(12) itaconic anhydride and

(13) aconitic anhydride

also manufactured:

(1) 3 ^f -0-acetyl-ara-cytidine (III)

(2) 3'-0-PiVoIyI-STa-CyWdIn (III)

(3) 3'-0-01eyl-ara-cytidine (III)

(4) 3'-0-nicotinyl-ara-cytidine (III)

(5) 31-0-1-naphthoyl-ara-cytidine (III)

(6) 3'-0- (1-adamantane acetyl) - ara -cytidine (III)

(7) 3'-O-cyclobutanecarbonyl- ara -cytidine (III)

(8) 3'-O-picolinyl-ara-cytidine (III)

(9) 3'-0-trans-3- (n-propyl) -hygroyl-ara-cytidine (III)

(10) 3 -O-SuocLnyl-ara-cytidine (III)

(11) 3 «-0- (3,3-dimethyl-glutaryl) -ara-cytidine (III)

(12) 3 ^I -0-Itaconyl-ara-cytidine (III)

(13) 3'-0-aconityl-ara-cytidine (III)

and the corresponding 2 ^f -0-acylates (I) of ara-cytidine.

Example 2 2 «-0 and 3'-O-stearyl-ara-cytidine (I and III)

17 g (30.8 millimoles) of stearic anhydride are added to a solution of 19.8 g (30 millimoles) of N-trichloroethoxycarbonyl-5'-O-trityl- ara -cytidine (VII) in 150 ml of anhydrous pyridine. The mixture is stirred at room temperature and after about 5.5 hours most of the stearic anhydride has reacted and only a small amount of insoluble material remains. After stirring for about 48 hours, some insoluble stearic anhydride is still present and the reaction mixture is warmed to about 50 ° C. for about 2 hours. Then all of the stearin

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acid anhydride reacts, but shows the thin layer chromatography (Solvent system: chloroform-methanol in a ratio of 95: 5) still contains a small amount of starting compound (VII) and three other components in the reaction mixture.

The reaction mixture is concentrated in vacuo to a solid residue which is dissolved in 100 ml of ethyl acetate oil and concentrated again in vacuo to remove the excess pyridine. The treatment with ethyl acetate and the concentration in vacuo are repeated twice and the residue obtained is then dissolved in 300 ml of ether. About 2.9 g of insoluble material are separated off. The clear ether solution is then extracted successively with 300 ml and 150 ml portions of a freshly prepared 1% sodium bicarbonate solution to remove the stearic acid, and the ether layer is dried over 75 g of anhydrous sodium sulfate. After the sodium sulfate has been filtered off, the clear ether filtrate is concentrated in vacuo. 33.1 g of a solid residue are obtained. A portion is examined by thin layer chromatography (solvent system: chloroform-methanol in the ratio 98: 2), which shows three different products with the R _f value 0.53, 0.15 and 0.07.

The product mixture is separated by chromatography over 2.5 kg of silica gel using a mixture of 98 % methylene chloride and 2 % methanol as the solvent system (chromatography A). After about 13 solvents have passed through the column, the EIution R _e action begins and products are collected 30,120 ml Fraktiaren. Fractions 1 to 4 mainly contain 2'-0, 3'-O-distearyl-N -trichloroethoxycarbonyl-5 · O-trityl-ara-cytidine (X), which give 6.27 g of material on evaporation. Fractions 5 to 18 contain a mixture of 3'-O-Sterayl ~ N -trichlorethoxycarbonyl-5 ^! -0-

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trityl ara- cytidine (. JX) and 2 "-O-stearyl ΪΓ-trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (VIII) and? 2 '-0, 3'-O-distearyl-N - trichloroethoxycarbonyl-5'-O-trltyl- ara- · cytidine (X). Evaporation of these fractions gives about 16.76 g of material. Fractions 19 to 30 contain about 0.5 g of product which was found to be a mixture of 2'-O-stearyl-N -trichloroethoxycarbonyl-5'-O-trityl- ara -cytidine (VIII) and some slower moving components .

The material weighing 16.76 g from fractions 5 to 18 is further purified by chromatography over 1 kg silica gel using about 10 1 methylene chloride and then 8 1 of a mixture of 99 % methylene chloride and 1 % methanol (chromatography B). When the UV absorption indicates that the products are beginning to elute, 22 ml fractions are collected. About 250 fractions are collected and examined by thin layer chromatography (solvent system: chloroform-methanol in a ratio of 98: 2). Fractions 1 and 2 mainly contain the disubstituted derivative 2 ^f -0, 3'-0-disfearyl-N * -trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (X). Fractions 3 to 50 contain a mixture of this distearyl derivative (X) and the monostearate, 3'-O-stearyl-N ^ -trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (IX). Evaporation of these fractions gives 6.4 g of material. Fractions 51 to 70 consist of fairly pure 3'-O-stearyl-N -trichloroethoxycarbonyl-5'-0-trityl ara -cytidln (IX). On evaporation, 720 mg is obtained. Fractions 71 to 90 also consist of this compound (IX) and give 380 mg on evaporation. Fractions 91 to 220 represent mixtures of the two monostearates, 3 '-0-stearyl-N ^{/ f} -trichloroethoxycarbonyl-5' -O-tritylara-cytidine (IX) and 2 '-O-stearyl-IT'-trichloroethoxycarbonyl-51 -O-trityl-ara-cytidine (VIII). Weighing 6.4 g

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Fractions 3 to 50 are chromatographed again on silica gel and removed most of the 2 · -0 _f 3'-O-distearyl-N ^ -trichloroethoxycarbonyl-S ^! -0-trityl- ara- cytidins (X) eluted first with chloroform containing 0.75 % ethanol and then with a mixture of 2.75 % ethanol-97.25 % chloroform, whereupon 3'-O-stearyl-IT -trichlorethoxycarbonyl-5'-O-trityl-era-cytidine (IX) is obtained. All fractions are examined by thin layer chromatography and those containing the desired product (IX) are pooled.

The entire 3 ^f -O-stearyl-N -trichloroethoxycarbonyl-5'-0-trityl- ara- cytidine (IX) with a weight of 1.36 g is dissolved in 50 ml of chloroform which contains 2 Vol.96 trilluoroacetic acid, and the reaction mixture is left to stand at room temperature for about 3.5 hours. Thin-layer chromatography no longer shows any starting material and thus the complete removal of the 5'-O-trityl group. The reaction mixture is washed twice with 100 ml of a freshly prepared saturated sodium bicarbonate solution each time, dried over sodium sulfate and concentrated in vacuo. The NT-trichloroethoxycarbonyl group is removed by dissolving the residue in 100 ml of methanol and refluxing it with 2 g of zinc for about half an hour. After filtering off the zinc, the solution is evaporated in vacuo, whereupon crude 3'-O-stearyl-ara-cytidine (III) is obtained. The product is purified by chromatography on silica gel. After the impurities are eluted with chloroform and a mixture of 2% methanol and 98,96 chloroform, the desired compound (III) is eluted with a mixture of 5% methanol and 95 % chloroform. 50 ml fractions are collected. Fractions 4 to 8 are combined. After recrystallization from acetone, they give the purified 3'-O-stearyl-ara-cytidine (III).

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Analysis; Calculated for

C 63.62; H 9.30; N 8.24; found: C, 63.30; H 9.18; N 8.47

UV 215 πιμ, light shoulder
230 πιμ, £ = 7 900 (shoulder)
272 mu, £ = 9 100 (shoulder)

Fractions 19 to 30 of chromatography A and 91 to 220 of chromatography B are combined and evaporated. The material obtained is chromatographed again as in chromatography B and those fractions which essentially only contain compound VIII (free from IX and X) , are disconnected. The protective N-trichloroethoxycarbonyl and 5'-O-trityl groups are removed as in the 3'-0-stearyl monoester (IX). The crude product (III) is purified as above and gives pure 2'-0-stearyl- ara- cytidine (i).

Following the procedure of Example 2 using the following acylating agents

(1) propionic anhydride

(2) valeric anhydride

(3) trifluoroacetic anhydride

(4) phenylacetic anhydride

(5) p-anisoyl chloride

(6) 2-furoyl chloride

(7) 4-thianaphthene acetyl chloride

(8) Cumaryl chloride

(9) fumaric chloride
(10) adipic anhydride

feretör manufactured:

(1) 310-propionyl-ara-cytidine (III)

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(2) 3'-O-valeryl-ara-cytidine (III)

(3) 3 ^! -0-trifluoroacetyl-ara-cytidine (III)

(4) 3'-O-phenylacetyl- ara -cytidine (III)

(5) 3'-0-p-anisoyl-ara-cytidine (III)

(6) 3 ^l -0-1-furoyl-ara-cytidine (III)

(7) 3'-0-4-thianaphthenacetyl-ara-cytidine (III)

(8) 3 ^t -O-coumaryl-ara-cytidine (III)

(9) 3'-O-fumaryl- ara -cytidine (III)
(10) 3'-0-adipyl-ara-cytidine (III)

and the corresponding 2 -O-acylates. (I)

Example 3 3 ^f -O-Benzoyl- ara -cytidine (III)

To a solution of 6.6 g (10 millimoles) of N-trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (VII) In 75 ml of anhydrous pyridine, 2.8 g (12.4 millimoles) of benzoyl chloride are added. The mixture is stirred at room temperature for about 16 hours, then another 0.5 g of benzoyl chloride in 10 ml anhydrous pyridine added. The mixture is stirred for about 4.5 hours at 50 to 55 ° C, then cooled to room temperature and stir for about 16 hours. The solution is then concentrated in vacuo to a thin syrup. This material will dissolved in ethyl acetate and evaporated in vacuo. Repeat this procedure twice and the crude residue 10.3 g is then dissolved in 12 ml of ethyl acetate. At the When standing at room temperature, 1.43 g of the starting compound (VII) separate out as a crystalline solid. The FiI kicked consists of a mixture of at least three components including some starting compound (VII). Chromatography on silica gel using ethyl acetate-cyclohexane (80:20) gives the starting compound (VII) is removed and 5.08 g of a material consisting essentially of two components with the R values is obtained 0.66 and 0.75 (thin layer chromatography with silica gel and ethyl acetate), this material is over Silica gel and chromatographed with ethyl acetate-cyclo-

209833/1221

hexane (40:60) eluted, collecting 15 ml fractions. The tubes 140 to 210 contain 2'-0, 3'-O-dibenzoyl-N -trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (X) and "the tubes 310 to 360 contain 2 · -O-benzoyl-N ^ -trichlorethoxycarbonyl-5'-O-trityl- ara -cytidine (VIII) and 3'-0-BeIZOyI-N ⁴ -trichlorethoxycarbonyl-5'-O-trityl-ara-cytidine (IX) the 3'-O-benzoyl-IT ¹ -trichloroethoxycarbonyl-5'-O-tritylara-cytidine (IX) separated, which moves / immediately before the corresponding 2'-0-benzoyl compound (VIII) <sicb>. If desired, the fractions containing the compound VIII can also be collected separately and processed in the same way as below to give 2 · -O-benzoyl-ara-cytidine (I).

The purified 3'-O-benzoyl-ΙΓ-trichlorethoxycarbonyl-5 · - O-trltyl- ara -cytidine (IX) is treated with a mixture of 80% acetic acid and 20 % water ₍ from the resulting 3 ' -Ö-Benzoyl-NH-trichlorethoxycarbonyl- ara -cytidine (IX ¹ ) is cleaved off the N -Trichloräthoxycarbonylgruppe by heating with zinc in methanol under reflux. The resulting crude material (III) is chromatographed over silica gel and eluting with cyclohexane-ethyl acetate- 95 tiger ethanol (5: 3: 1) and then with methyl ethyl ketone-ethyl acetate ^ -water (72: 20: 8) The desired fractions are combined, evaporated to a solid residue and recrystallized from acetone -Benzoyl-ara-cytidine (III) melts with slight decomposition at 208 to 210 ° C.

Analysis: Regarded for ^ gH ^ yOgN ^ j

C 55.33} H 4.931 N 12.10; Found: C, 55.26; H 5.08; N 12.28.

209833/1221

UV: 231 π> μ, f = 21,600
272 mu, £ = 10,700.

Following the procedure of Example 3 were made using the following acylating agents

(1) p-nitrobenzoyl chloride

(2) p_-toluoyl chloride

(3) 2,4,6-trimethylbenzoyl chloride

(4) 3,4,5-trimethoxybenzoyl chloride

(5) 2,6-dimethylbenzoyl chloride

also manufactured:

(1) 3 ¹ -Op-nitrobenzoyl- ara- cytidine (III)

(2) 3 ^t -0-o-toluoyl-ara-cytidine (III)

(3) 3 «-O-2,4,6-trimethylbenzoyl-ara-cytidine (III)

(4) 3'-0-3.4.5-trimethoxybenzoyl- ara -cytidine (III)

(5) 3'-0-2.6-dimethylbenzoyl ara- cytidine (III)

and the corresponding 2'-0-acylates of the ara-cytidine (I).

Example 4 2 "-0-, 3'-0- and 2", 3'-Di-O-methoxycarbonylaracytidine (I, III and V)

To a solution of 6.6 g (10 millimoles) of N ^ -Trichloräthoxycarbonyl-5'-O-trityl-ara- cytidine (VII) in 25 ml anhydrous pyridine (about 10.6 millimoles) of methyl chloroformate is added 1 g. The mixture is stirred at room temperature for about 16 hours. The solvent is then evaporated off in vacuo, the residue is dissolved in ethyl acetate and chromatographed on a column of silica gel. After removing the 2'-0, 3'-0-di (methoxycarbonyl) -N -trichloroethoxycarbonyl-5'-O-trityl-ara-cytidine (X ¹ ) as a fast moving component (point A), the 2 '-0-Methoxycarbonyl-N -trichlorethoxycarbonyl-5'-O-trityl- ara- cytidine (VIII ¹ ) and the 3'-O-methoxycarbonyl-N -trichloroethoxycarbonyl-5' -O-trityl-ara-cytidine (IX) as mixture

209833/1221

eluted. They are chromatographed again to achieve separation (point B). The purified 3'-0-methoxycarbonyl-N -trichlorethoxycarbonyl-5 * -O-trityl- ara -cytidine (IX ¹ ) is hydrolyzed at the 5'-position by adding about 100 ml of a mixture of 80 % acetic acid and mixes 20% water at room temperature. The 3'-O-methoxycarbonyl-N -trichloroethoxycarbonyl- ara -cytidine (IX ") obtained is dissolved in about 50 ml of methanol and refluxed with about 1 g of zinc dust until the trichloroethoxycarbonyl group at the N position has been removed the reaction is followed by thin layer chromatography. When it is complete, the zinc is filtered off and the filtrate is concentrated in vacuo to a solid residue. The product is recrystallized from boiling methanol. The pure 3'-0-methoxycarbonylaracytidine (III) is obtained .

The 2 ¹ , 3 ^! -Di-0 derivative X ¹ from point A and the 2'-0 derivative VIII ¹ from point B are each treated separately as described for the 3'-0 derivative IX ¹ and result in purified 2 ' ₁ 3'- Di-O-methoxycarbonyl- ara -cytidine (V) and 2'-O-methoxycarbonyl- ara -cytidine (I).

Following the procedure of Example 4 using the following acylating agents

(1) ethyl chloroformate

(2) carbobenzoxy chloroformate

(3) octyl chloroformate

(4) palmityl chloroformate

(5) phenyl chloroformate

also manufactured:

(1) 3 ^f -O-ethoxycarbonyl- ara -cytidine (III)

(2) 3'-O-carbobenzoxycarbonyl- ara -cytidine (III)

(3) 3 ^! -O-octyloxycarbonyl- ara- cytldine (III)

209833/1221

(4) 3'-O-palmityloxycarbonyl- ara -cytidine (ill)

(5) 3'-O-phenyloxycarbonyl- ara -cytidine (III)

and the corresponding 2'-O- and 2 ¹ , 3 »-Di-O-acylates of ara-cytidine.

Example 5 A 3'-0, S'-O-Dipalmityl-ara-cytidine (IV)

A suspension of 200 g (0.72 mol) of the known ara- cytidine hydrochloride (XIa) in 1.5 l of dimethylacetamide is stirred until most of the solid has dissolved. 393 g (1.43 mol) of palmityl chloride are added dropwise over about an hour, and the reaction mixture is stirred for about 16 hours at room temperature. A thick white sludge is formed, which is poured into 6 liters of ethyl acetate-ether (1: 1). It is then filtered, washed with ethyl acetate-ether (1: 1) and then with ether and dried in vacuo. 370 g of a crude solid are obtained. This material (IVa) is stirred with 4 1 0.5 η sodium bicarbonate solution for about 2 hours, filtered, carefully washed with water and sucked dry on a filter. The crude filter cake is recrystallized from 5 liters of boiling methanol and after standing in a refrigerator for about 16 hours, 180 g of a solid are obtained '-0, 5'-O-DipLmityl-ara-cytidins (IV) - with a main component (R ~ = about 0.45 in chloroform-methanol - 9: 1 »silica gel plates) and an impurity (R _f = 0.87 in chloroform-methanol - 9: 1, silica gel plates). This material (weighing 4.5 g) is purified by column chromatography using 99.25 % chloroform and 0.75 % ethanol as solvents until the solid material begins to elute from the column. The solvent system is then exchanged for a mixture of 98 % chloroform and 2 % ethanol and it is

209833/1221

the 70 ml fractions collected. Fractions 1 to 22, which _{contain material with an R f} value of 0.87, are discarded. Fractions 36 to 60 contain very little of the desired material and a mixture of 3 % ethanol and 97 % chloroform and finally a mixture of 5 % ethanol and 95 % chloroform are now used for the elution before the elution of the desired product IV begins. 3.2 g of product IV are obtained. About 2.2 g of this are recrystallized from 110 ml of boiling methanol. On cooling, 2.1 g of 3'-0, 5'-O-dipalmityl ara cytidine (IV) with a melting point of 111 to 112 ° C. (shrinks at 88 ° C., becomes glassy at 98 ° C. and flows at 111 ° C.) are obtained sharp up to 112 ° C).

Analysis; Calculated for C ^ HL-, OyN ,:

C 68.39; H 10.22; N 5.84; Found: C, 68.37; H 10.21; N 5.97

R. = 0.42 (solvent system chloroform: methanol - 9: 1, Silica gel plates). The structure of the compound is confirmed by the nuclear magnetic resonance (NMR) spectrum.

Following the procedure of Example 5 using the following acylating agents

(1) isobutyryl chloride

(2) octanoyl chloride

(3) stearyl chloride

(4) β-chloropivaloyl chloride

(5) p_-toluoyl chloride

(6) tetrahydrofuroyl chloride

(7) isonicotinyl chloride

also manufactured:

(1) 3'-0, S'-O-diisobutyryl-ara-cytidine (IV)

(2) 3'-0.5'-0-dioctanoyl-ara-cytidine (IV)

209833/1221

(3) 3'-O, 5 ^l -O-distearyl-ara-cytidine (IV)

(4) 3'-O, 5'-0-Di (B-ChIOrPiVaIOyI) -BTa-CYtXdIn (IV)

(5) 3 * -0, 5'-0-di (p_-toluoyl) -aiva-cytidine (IV)

(6) 3'-0, 5 · -O-di-tetrahydrofuranoyl-ara-cytidine (IV) and

(7) 3'- ^{0.5 t} -0-diisonicotinyl-ara-cytidine (IV)

Example 5 B

In the process of Example 5A, with careful monitoring, for example by UV absorption of silica gel plates produced by thin-layer chromatography, it is found that the acylates formed in the acylation are eluted in two closely successive maxima. The material of the first peak is composed of 3 ', 5'-di-O-palmityl-ara-cytidine, and the subsequent peak of 2'.5'-di-O-palmityl ara- cytidine. The 2 ', 5 x -di-O-palmityl ara- cytidine fractions are separated and after that in Example 5 A procedure described for the working up of 3 ^1, 5'-di-0-ester treated, followed by 2', 5'-Di-O-palmityl ara- cytidine is obtained.

Example 6 3'.5 ^f -Di-O-palmityl- ara -cytidine (IV) from

protonated 2,2'-anhydro-ara-cytidine (XIIb)

1.3 g of 2,2'-anhydro-ara-cytidine (XIIb) are suspended with stirring in 50 ml of dimethylacetamide. A solution of 3.0 g of palmityl chloride in 25 ml of dimethylacetamide is then added. The mixture is stirred at 55 ° C. for about 160 hours. About 0.2 g of insoluble material is filtered off and the filtrate is concentrated in vacuo to a solid residue. By chromatography over silica gel using methyl ethyl ketone-acetone-water 72: 20: 8, the separation of the 3'-0 5'-O-dipalmityl ara- cytidine (IV) of three other components of the reaction mixture ~ with lower R values achieved.

209833/1221

Example 7 3 ¹ , 5 ^f -Di-0-benzoyl-ara-cytidine (IV) from 2,2 · anhydro-ara- cytidine (XIIa)

5.22 g of 2,2'-anhydro-ara-cytidine (XIIa) are suspended in 160 ml of anhydrous pyridine with stirring. 9 g of benzoyl chloride are added dropwise with stirring over a period of about 2 hours. The solid continues to convert and after 16 hours the solution is clear. To complete the reaction, the solution is heated on a steam bath for 1.75 hours and then gives mainly a single spot with an R «value of 0.72 (chloroform-methanol 90:10). The reaction mixture is concentrated in vacuo to remove the pyridine. The residue is dissolved in absolute ethanol and evaporated again to remove traces of pyridine. This procedure is repeated three times. The semi-solid material obtained is slurried in 50 ml of methanol and filtered. The solid is washed once with cold methanol and then recrystallized from boiling methanol. 4.33 g with a melting point of 197.5 to 198.5 ° C. are obtained. A further 2.95 g are obtained from the various filtrates. The analysis showed that this material was 3 ^! -0, 5'-0, N tribenzoyl- ara -cytidine hydrate (XV) acted. 1.5 g of 3'-0, 5'-0, N -tribenzoyl- ara -cytidine hydrate are dissolved in 15 ml of a mixture of pyridine and acetic acid in a ratio of 4: 1, and 0.45 ml of hydrazine hydrate are added. The solution is stirred for one hour at room temperature and then placed in a refrigerator overnight. The solvent is evaporated and the residue is chromatographed over silica gel using methylene chloride-methanol 95: 5. The fractions containing the desired product are combined and recrystallized from methanol-water. 538 mg of 3'-0, 5'-O-dibenzoyl- ara -cytidine hydrate (IV) with a melting point of 247 to 248 ° C. (decomposition) are obtained. A small amount of yellow material is removed by repeated chromatography as described above.

209833/1221

The purified 3'-O, 5'-O-dibenzoyl-ara-cytidine hydrate (IV) crystallizes in the form of fine white needles and melts at 247-248 ° C (decomposition.

Analysis: Calculated for C ^ H _0. , O ₇ IJVH ₀ O:

C 58, u4; H 4.94; W 8.95; Found: C, 59.28; H 4.61; N 9.11

UV spectrum
must

232 32 000

268 (wide 9 850
Maximum)

282 (light 6 950
Shoulder)

NMR: corresponds to the structure

Example 8 3 ^! -0-palmityl-ara-cytidine (III) from 2,2'- anhydro-ara- cytidine (XIIb)

26.07 g (0.1 mole) 2.2 ^! Anhydro-ara-cytidine hydrochloride (XIIb) is mixed with 500 ml of pyridine. About 30.7 g (0.11 mol) of triphenylchloromethane are then added and the mixture is stirred for about 120 hours at room temperature. The excess solvent is removed in vacuo and the residue is carefully triturated several times with benzene and decanted to remove the excess triphenylchloromethane and de3 pyridine. The residue is then dissolved in dry thyme thy 2 formamide, and the dimethylformamide is evaporated off in vacuo to remove the remaining Ikmzols (pressure below 1 mm). The crude 5-O ~ trityl-2, P .'-anhydro- ara -cytidiuhydiOchloricl (XVTI) obtained is treated with 300 mg of dry dimethylforma Ld according to and within 2 3 hours tropi'etiwöisii with a spray of 30 , 24 g (0.11 mol) of painitoyl chloride in 200 ml of dry dimethylformamide

2 0 9833/1221

offset. The reaction is allowed to proceed for about 24 hours. The solvent is then removed in vacuo and the reaction product obtained is purified by chromatography on silica gel. The purified 5'-O-trityl-3'-O-palmityl-2,2'-anhydro-ara-cytidine (XVIII) hydrochloride is dissolved in glacial acetic acid and mixed with water with stirring until the onset of turbidity. The clear solution is heated to about 40 ° C. for 16 hours to remove the 5'-O-trityl substituent. The reaction mixture obtained is then concentrated in vacuo and the residue is extracted with ether to remove the unreacted palmitoyl chloride and triphenylmethylcarbinol. Then it is carefully treated with 2% sodium bicarbonate solution to completely hydrolyze the anhydride ring and to neutralize the hydrochloride. The crude 3'-O-palmityl- ara- cytidine (III) obtained is dried in vacuo. It can be purified further by recrystallization from methanol or by chromatography over silica gel and subsequent recrystallization from methanol.

Example 9 2 '. 3'-Di-O-palmityl- ara ^ -cytidine (V) using Method A.

19.8 g (30 millimoles) of N ^ -trichloroethoxycarbonyl-5'-0-trityl ara -cytidine (VII) are dissolved in 150 ml of anhydrous pyridine. Then 16.4 g (33 millimoles) of palmitic anhydride are added. The suspension obtained is stirred overnight and the reaction of the solid palmitic anhydride results in a clear solution. The reaction mixture is concentrated to a syrup in vacuo. The syrup is dissolved in ethyl acetate and evaporated in vacuo, and this solution and evaporation is repeated twice. The syrup finally obtained (about 39 g) is dissolved in 500 ml of ether and mixed with 300 ml of a freshly prepared 1 ^ igen sodium bicarbonate solution and then three times with each

209333/1221

Washed 70 ml of water. The ether layer is over anhydrous Dried sodium sulfate and removed the solvent. 34.8 g of a syrupy residue are obtained. the Thin layer chromatography using silica gel and cyclohexane-ethyl acetate 1: 1 gave three Main components with the R value 0.78 and 0.39, the latter appeared as a double stain.

The syrup is chromatographed over 2.5 kg of silica gel using ethyl acetate as the elution solvent. As soon as UV absorption is observed in the outflowing material, 200 ml fractions are collected. From a total of 32 fractions, the fractions 1 to 4 containing about 5.07 g of purified N-trichloroethoxycarbonyl-5 -0 ^l-trityl-2 ', ^3-di-t 0-palmityl-ara-cytidine (X). Fractions 4 to 32 contain approximately 16.34 g of solids with three components distinguishable by thin layer chromatography in most of the fractions. These 16.34 g of solids are chromatographed again over silica gel, ethyl acetate-cyclohexane 1: 1 being used for the elution. When the elution of products is indicated by UV absorption, 100 ml fractions are collected. Fractions 1 to 60 contain about 6.98 g of compound X. Fractions 1 to 14 from the first column above are combined to give 12.05 g of compound X. This material is dissolved in 200 ml of a mixture of 80 % acetic acid and 20% % Water dissolved and mixed with 12 g zinc dust. _O The mixture is stirred overnight The zinc residue is filtered off and the filtrate is heated for complete removal of the protective trityl group 5 ^l -0-two hours on a steam bath. The solution is then concentrated to dryness in vacuo and the dry residue is dissolved in chloroform and washed twice with 200 ml of water each time. After drying the chloroform layer over anhydrous sodium sulfate and concentrating in vacuo,

209833/1221

one holds a solid residue. It is recrystallized twice from acetone and gives 3 »4 g of crystalline 2 ^I , 3 ^I -Di-O-palmityl- ara -cytidine (V) with a melting point of 144 to 145 ° C.

Analysis; Calculated for C ^ Η, - ,, ΟγΝ · ,:

C 68.39; H 10.22; N 5.84; Found: C, 68.16; H 10.26; N 6.07

ÜV: 238 my; £ = 7,800
271 mu; fc = 8 250

Thin-layer chromatography: silica gel plates, solvent system chloroform / methanol 95: 5, R _£ = 0.22.

209833/1221

Claims (26)

Claims Connections of the general formulas NH, ZOCH ₂ OH NH, N ""
0 ^ N ZOCH, I, II III, IV OY HIGH 209833/1221 - THU - in which Y (1) RC- denotes, where R is an aliphatic radical with 1 to 20 carbon atoms, an aromatic radical with 6 to 10 carbon atoms, a hydrocarbon residue of the cage type with 7 to 20 carbon atoms, a monocyclic aliphatic radical with 4 to 10 carbon atoms, an araliphatic R6st with 7 to 12 carbon atoms or a monocyclic heterocyclic Radical with 4 to 10 carbon atoms, and the radicals mentioned by halogen atoms, hydroxy, carboxy, nitro, Alkoxy or mercapto groups can be substituted, or Q (2) R-OC-, where R 'is an aliphatic radical with 1 to 20 carbon atoms, an aromatic radical with 6 to 10 carbon atoms or an araliphatic radical with Is 7 to 12 carbon atoms and Z has the same meaning as Y or hydrogen, and their pharmaceutically acceptable acid addition salts. 2. Compounds according to claim 1, in which Z is hydrogen. 3. 2 • -O-palmityl-ara-cytidine. 4. 2'-O-stearyl-ara-cytidine. 5. 2 · -O-methoxycarbonyl- ara -cytidln. 6. Compounds according to claim 1, in which Y and Z represent the RC group. 7. 2 », 5 · Di-O-palmityl-ara-cytidine. 209833/1221 8. 3'-O-methoxycarbonyl- ara- cytidine. 9. 3'-O-palmityl-ara-cytidine. 10. 3'-O-stearyl- ara- cytidine. 11. 3'-O-benzoyl-ara cytidine. 12. 3 ', 5'-Di-O-palmityl-ara-cytidine. 13. 3 ', 5'-di-O-benzoyl-ara-cytidine. 14. 2 ', 3'-di-O-methoxycarbonyl-ara- cytidine. 15. 2 ', 3'-Di-O-palmityl- ara -cytidine. 16. A process for the preparation of compounds according to claim 1 with the general formulas 209833/1221 HIGH III ) CR NH, HIGH, OCR in which R has the meaning given above, characterized in that one (1) a compound of the formula 209833/1221 with a Trihalogenäthoxycarbonylhalogenid of the general formula O CX ^ CH ₀ OCX in which X is chlorine or bromine, to a compound of the general formula NH-C-OCH ₀ CX, l 2 3 VII implements, (2) the compound obtained to give compounds of the general formulas L NHC-OCH ₂ CX ₃ -COCH ₂ VIII OH 209833/1221 IX OCR acylated, in which X and R have the meaning given above, (3) separating the acylation products from one another and (4) hydrolyzes them at the 5'-O and N positions. 17. The method according to claim 16, characterized in that that the hydrolysis of the 5'-O- and the N -position is carried out before the separation of the acylation products. 18. Process for the preparation of compounds according to claim 1 with the general formulas 209833/1221 HIGH )H NH, HIGH ΙΙΓ HIGH 209833/1221 in which R 'has the meaning given above, characterized in that one (1) a compound of the formula VI with a Trihalogenäthoxycarbonylhalogenid of the general formula CX ₃ CH ₂ OCX in which X is chlorine or bromine, to a compound of the general formula NHCOCH ₂ CX ₃ COCH, VII OH 09833/1221 implements, (2) the obtained compound with an acylating agent the general formula p
R ¹ OCCL in which R ^{1 has} the meaning given above, in compounds with the general formulas NHCOCH ₂ CX ₃ VIII ' NHCOCH ₉ CX, IX ¹ 209833/1221 NHCOCH ₂ CX ₃ Χ · OCOR ¹ convicted, (3} separates the acylation products from one another, (4) from them the 5'-0-trityl group with formation of Connections of the general formulas Il NHCOCH ₀ CX I ² HIGH VIII » OH 209833/1221 HIGH NHCOCH ₂ CX ₃ IX " NHCOCH ₀ CX 2 X " removed by hydrolysis and , X k (5) the compounds thus obtained are hydrolyzed at the N position. 19. The method according to claim 18, characterized in that the hydrolysis of the 5'-O position is carried out before the separation which carries out acylation products. 20. Process for the preparation of compounds according to claim 1 with the general formulas 209833/1221 RCOCH OH II IV in which R has the meaning given above, characterized in that, that he (1) a compound of the general formula HIGH GH 2C9833 / 1221 XIa in which w® is the anion of a strong acid, to compounds the general formulas O u RCOCH Ha IVa acylated, (2) this neutralizes and removes the proton at the N position (3) separates the acylation products. 21. A method for the preparation of compounds according to claim with the general formula 209833/1221 Y OCH, IV ¹ OY ' in which Y ^{1 is} an aromatic acyl radical having 6 to 12 carbon atoms, characterized in that one (1) a compound of the formula HOH ₂ C XIIa with an acylating agent of the general formula Y'OY «or Y ¹ X ₁ in which Y ^{1 has} the meaning given above and X _{1 is} chlorine, bromine or iodine, to a compound of the general formula 209833/1221 Y'OHoC XIII implements, (2) from it the N -acyl group to form a compound of the general formula NH Y'OH XIV selectively removed and (3) hydrolyzes the 2,2'-anhydride bond. 22. A method for the preparation of compounds according to claim 1 with the general formula 209833/12 21 NH, YOCH IV Ii in which Y is the group RC- or R ¹ OC-, where R and R 'have the meanings given above, and of their acid addition salts, characterized in that one (1) a compound of the general formula HOH ₂ C XIIb in which w ^{w is} the anion of a strong acid, with an acylating agent of the general formula YOY or YX ₁ in which Y has the meaning given above and X _{1 is} chlorine, bromine or iodine, to a compound of the general formula 209833/1221 YOH ₂ C XVI implements and (2) hydrolyzes the 2,2'-anhydride bond. 23. A process for the preparation of compounds according to claim 1 having the general formula NH, HIGH III in which Y is the group RC or R ¹ OC, where R and R ^! have the meaning given above, characterized in that one (1) a compound of the general formula 209833/1221 HIGH XIIb in which w ^ is the anion of a strong acid, with a triphenylmethyl halide to form a compound of the general formula XVII implements, (2) them with a compound of the general formula YX ₁ or YOY in which Y has the meaning given above and X ^ is chlorine, bromine or iodine, into a compound of the general formula 209833/1221 XVIII convicted, (3) Add the compound obtained at the 5'-O position a compound of the general formula HIGH ₂ XIX hydrolyzed and (4) the compound thus prepared is hydrolyzed to a compound of the general formula III. 24. Compound of the general formula 209833/1221 w © XVII in which w ^ is the anion of a strong acid. 25. Compound of the general formula XVIII ■ OY 0 Il OC is where R and R ¹ in the Y the group RC or R ¹ have the meaning given above, and w ^ the anion a strong acid. 26. The compound of claim 25, wherein the RC group is the palmityl group. For The Upjohn Company Kalamazoo, Mich., V.St.A. Dr. H. S. Wolff Attorney at Law 209833/1221