WO1996028413A1

WO1996028413A1 - Synthesis of amidocarboxylic acid derivatives

Info

Publication number: WO1996028413A1
Application number: PCT/US1996/003181
Authority: WO
Inventors: Brian D. Condon
Original assignee: Hoechst Celanese Corporation
Priority date: 1995-03-16
Filing date: 1996-03-07
Publication date: 1996-09-19

Abstract

A new synthetic route for the manufacture of a class of compounds known as amidocarboxylic acids and their derivatives are disclosed.

Description

SYNTHESIS OF AMIDOCARBOXYLIC ACID DERIVATIVES

Field of the Invent on

In general, this invention relates to a new synthetic route for the manufacture of a class of compounds known as amidocarboxylic acids and their derivatives.

Background of the Invention

Typically amidocarboxylic acids find applications as water soluble metal corrosion inhibitors when used in basic (pH > 8.5) aqueous systems. Such compounds may be dissolved in water at levels of about 0.1 - 50 percent by weight and mixed with an organic amine base such as monoethanolamine, diethanolamine, triethanolamine, isopropylamine, isopropanolamine and cyclohexylamine . The pH may be raised further with any common inorganic base such as sodium hydroxide. Metal parts may then be soaked in such solutions to effect protection against corrosion. Current methods of preparing such compounds include the Shotten-Bauman reaction wherein an alkyl carboxylic acid chloride is reacted with an amine to produce an amide. Amino substituted carboxylic acids are necessary reactants to produce amido-carboxylic acids using the Shotten-Bauman reaction. However, the use of amino substituted carboxylic acids in place of the amine complicates the reaction because polymerization of the amino substituted carboxylic acid easily occurs. With these current methods, multi-step synthesis is required, large amounts of NaCl are generated (requiring several washing steps for removal) , and the whole sequence is usually no more than 70% efficient based on the initial amount of carboxylic acid used.

Previous attempts at improving alkylation chemistry include the following:

Fones, W.F., Journal of Organic Chemistry. Volume 14, 1099 (1949) describes an improvement to older techniques of N-alkylation of amides that uses one molar equivalent of sodium hydride in refluxing toluene to make the N-sodio amide which is then alkylated with an alkyl halide .

Norlander, J.E., Tetrahedron Letters. Volume 50, 4987 (1978) describes the reaction of trifluoacetamides with a full equivalent of potassium hydride in dry tetrahydrofuran as solvent at 0 degrees C. The product of this reaction is then reacted with an alkyl halide to give the alkylated amine. Johnstone, R.A., Tetrahedron, Volume 35, 2169 (1979) outlines a method for N-alkylation of amides using dry dimethylsulfoxide as solvent, four mole equivalents of potassium hydroxide, a catalytic amount of 18-crown-6 and two mole equivalents of alkyl halide. Reaction is complete in about one hour at room temperature.

Zwierzak, A., Synthesis. 1005 (1981) teaches the alkylation of amides in boiling benzene using three mole equivalents of sodium hydroxide, two mole equivalents of potassium carbonate, a catalytic amount of tetrabutylammonium bisulfate and three equivalents of alkyl halide.

None of these methods, however, have resulted in processes which are simple, inexpensive, give high yields with little or no waste salt, and which do not require the use of hazardous materials.

Thus, it is an object of this invention to provide a new synthetic route for making selected amidocarboxylic acid derivatives wherein the process provides higher yields of product with less waste formation than in current methods. It is a further object of this invention to provide processes which reduce or eliminate the use of hazardous materials and which use fewer steps to accomplish the synthesis. These and other objects of the invention will be apparent from the following description.

Summary and Detailed Description of the Invention This invention comprises an improved method for synthesizing compounds of Formula I:

(R^'-C0NHR²C00M_x M^*κ

Formula I where:

R¹ = any organic group not containing acidic hydrogens ar.d which has a pKa less than about 16. Particular values for R^'- are C_: - C,^, straight or branched chain alkyls and alkenyls, and benzyl optionally substituted by one or two members selected from the group consisting of C_ι.-C_ιs alkyl and alkenyl, and wherein the R¹ group may optionally be substituted with a member of the group consisting of, for example, fluorine, chlorine, bromine, iodine, -OR³⁰, -C(0)OR³¹, NH₂,

0 0 0 0 0

S-R ⁴⁶ , — S 1- _R- , — S-R^4β , — S-OR⁴\

O 0 —0—S-OR⁵⁰ ,

where R³⁰ - R^5: are each selected independently from the group consisting of C_ - C₁₀₀ straight or branched chain alkyls and alkenyls, and benzyl optionally substituted by one or two members selected from the group consisting of C_t-C_ιs alkyl and alkenyl. Particular values for R¹ are C₅ - C_so alkyls and alkenyls and more particular values for R¹ are C₇ - C₂₀ alkyls and alkenyls.

R² = any organic group not containing acidic hydrogens and which has a pKa less than about 16.

Particular values for R² are C₂ - C_2D straight or branched chain alkylenes and alkenylenes, wherein R² is optionally substituted with a member of the group defined above for substitutions of R¹. More particular values for R² are C₂ - C₂₀ alkylenes ar.d alkenylenes, and even more particular values are C₂ - C_:: alkylenes and alkenylenes.

M = a member of the group consisting of hydrogen, alkali metal cations, alkaline earth metal cations, and ammonium cation; particularly sodium, potassium, lithium, calcium, magnesium, monoethanol ammonium, diethanol ammonium and triethanol ammonium. x = 1 or 2 and is selected to satisfy the valence requirements of M. The improved method of this invention comprises the following steps. An acid of Formula II: R^ια-COOH, wherein R¹ has the same definition as R¹, is esterified with an alcohol of Formula III: R ^o-OH, wherein R²⁰ has the same definition as for R^l, including the more particularized values. A particular value for R²⁰ is C_ - Z_₎ alkyl and a more particular value is C, - C_ζ alkyl. The esterification process is known to proceed quan ita ively in a short reaction time (on the order of 24 hours) and with little or no creation of waste products to give the ester of Formula IV: R¹⁰-COOR²⁰. The ester of Formula IV is then mixed with a lactam of Formula V:

Formula V

wherein R² has a value as defined above in a ratio of from about 1:100 to 100:1 of ester IV to lactam V. More particular ranges for this ratio are from 1:20 - 20:1, with an even more particular range of 1:1. The mixture is then heated to a temperature in the range of 40 to 250 degrees C, more preferably in the range of 60 to 180 degrees C, and most preferably in the range of 100 to 140 degrees C, depending on the identity of the reactants . After temperature has been reached, catalyst is added (as described below) and the heating is continued until the reaction is complete. The reaction time is usually in the range of about 0.5 - 24 hours and typically in the range of about 1 - 3 hours. The catalyst system is comprised of:

(a) a first component selected from the group consisting of:

(i) an alkali metal alkoxide formed from the alkali metal salts of straight chain or branched C_x - C₁₀ alcohols, for example, sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, sodium tert- butoxide, potassium methoxide, potassium ethoxide, potassium propoxide, potassium butoxide, potassium tert-butoxide, lithium methoxide, lithium ethoxide, lithium propoxide, lithium butoxide and lithium tert-butoxide; (ii) metallated amines of Formula VI:

Q-N(R³) (R⁴) , wherein Q s selected from the group consisting of Group I and Group II metals, especially sodium, lithium and magnesium, and R³ and PM may be the same or different and are each independently selected from the group consisting of hydrogen and C-, - C₆ alkyls; and (iii) basic catalysts whose conjugate acid has a pKa greater than about 16, for example, metallated alkyls having 1-6 carbons wherein the metal portion is selected from the group consisting of, for example, lithium, sodium and magnesium (for example, sodium or lithium substituted methane or butane) and alkyl magnesium halides wherein the alkyl portion has from 1-6 carbons (for example, methyl magnesium chloride) . Potassium tert-butoxide is preferred.

Note that metallated amines of Formula VI may have a +1 charge if a member of Group II is used.

Optionally the catalyst system can have a second component (b) such as an acylation catalyst selected from the group consisting of dimethylformamide (DMF) , pyridine, N,N-dimethylaminopyridine, dimethylsulfoxide (DMSO) , dimethoxyethane, 18-crown-6, hexamethyl- phosphortriamide, tetrahydrofuran and dietnyl ether, but preferably DMF.

To the heated mixture described above is added about 0.001 - 35.0 mole equivalents, more particularly 0.001 - 3.0 mole equivalents, preferably about 0.01 - 1.0, and, most preferably, about 0.05 - 0.50 mole equivalents of component (a) and optionally component (b) of the catalyst system wherein the mole equivalents are based on the limiting reagent of either Formula VI or V (whichever is less) . It is to be noted that the same number of mole equivalents of (a) and (b) are not necessarily needed. It is also to be noted that DMF and the other acylation catalysts can serve as a solvent as well as part of the catalyst system, so that a large excess of DMF, for example, can be used while retaining the (a) component (for example, tert-butoxide) at the level of 0.001 - 3.0 mole equivalent.

The reaction mixture should be stirred gently during the reaction while maintaining the required temperature and anhydrous conditions. An inert atmosphere is preferred but not required. The completion of this reaction forms a compound of Formula VII :

R¹-C(0) -N(H) -R^:-COOR²⁰

Formula VII

which is the ester of Formula I, where M = R²⁰ and x = 1. The compound of Formula VII can then be manipulated to form a salt or acid form. For example, the compound of Formula VII can be hydrolyzed and acidified by using 0.3 - 3.0 mole equivalents of a mineral acid such as those selected from the group consisting of aqueous solutions of HCl, H_;S0 , H,P0 to give the corresponding acid form of the compound of Formula I, where M = H and x = 1. Also, the ester of Formula VII can be hydrolyzed under basic conditions using 0.3 - 50.0 mole equivalents of an organic amine base (for example, ammonium hydroxide, monoethanolamine, diethanolamine and triethanolamine) or inorganic base in aqueous solution. Particular examples of such bases include alkali metal hydroxides and alkaline earth hydroxides, examples of which include sodium hydroxide, lithium hydroxide, potassium hydroxide, calcium hydroxide and magnesium hydroxide, and especially sodium hydroxide. More particular ranges for such bases include 0.5 - 15.0 mole equivalent, such as 0.5 - 10.0 mole equivalents and, even more particularly, 1.0 - 2.0 mole equivalents. This reaction gives the sodium or organic amine salt with the liberation of an alcohol (R²⁰- OH) such as methanol . The alcohol such as methanol can be condensed and recycled. Such hydrolysis can be conducted under acidic or basic conditions. In practice, however, it has been found that basic conditions are more effective to hydrolyze the ester linkage while retaining the amide linkage of these compounds.

In another aspect of this invention, it has been found that an improved method of conducting the ester hydrolysis is preferred in order to obtain the salt form of compounds of Formula I . In theory one equivalent of base (for example, a base selected from the group consisting of NaOH, KOH, Ca(OH)₂, tributylamine, dicyclohexylamine, monoethanolamine, diethanolamine, triethanolamine, diisopropylamin , isopropanolamine, and mixtures thereof) and one equivalent of water are required for ester hydrolysis. In practice it has been found that the reaction becomes too viscous and that optimum conditions should use dilution of the reaction medium. Thus, sufficient water or other viscosity modifier is added to produce an aqueous slurry or emulsion of about 10 - 70 percent organic content, but preferably about 40 - 60 percent organic content. Then, to this slurry or emulsion is added about 0.2 - 10.0 mole equivalents, preferably 0.4 - 5.0 mole equivalents, and most preferably 0.7 - 3.0 mole equivalents of the base of choice based on the organic content. If inorganic bases are used, about 0.5 - 1.5 mole equivalents based on the organic content of the slurry or emulsion are optimum. The reaction medium is then heated to abut 100 degrees C. to begin the distillation of water. The water which is distilled off carries with it the hydrolyzed alcohol (R²³- OH) (for example, methanol) , catalyst (for example, DMF) , and small amounts of other products (for example, tert-butanol if potassium tert-butoxide has been used) . To maintain an optimum hydrolysis rate and reaction viscosity, water is added to the reaction medium at approximately the same rate as which it is distilled off. The viscosity should be maintained at a value which allows the reaction to be stirred. Once the hydrolysis is complete, the water content can be lowered as desired to produce a higher active product. The limits on the active content of the product of Formula I are determined by the viscosity and melting point of the product. These are different for each different salt form and acid form. The active content of the product can range from 10 percent to 100 percent. As will be appreciated by those skilled in the art, it is generally desirable to achieve a high active content, while forming a liquid which is pourable at room temperature .

Also, if the acid form of Formula I is desired, the pH may be lowered by addition of mineral acids as defined above to the hydrolysis reaction medium to a pH less than 7 and preferably in a range of about 1 to 4. In the acidic state, the subject molecules of Formula I where M is H and x = 1, are not soluble in the aqueous reaction medium and will precipitate as a solid or oily liquid. The precipitated acid form of Formula I can then be washed successively with fresh portions of water to remove the above listed catalysts, solvent (if any) and any inorganic or organic salts produced in the reaction, hydrolysis and subsequent pH adjustment.

It is important to note that there are impurities and molecular species that are incompatible with the successful practice of the process of this invention. Essentially any species which contains an acidic hydrogen atom with a DKa less than about 16 will interfere with the reaction and will neutralize the strongly basic alkali metal alkoxide catalyst. As long as the amount of these impurities is significantly lower than the amount of catalyst used, the reaction will still proceed. Generally it is preferred that the level of impurities be as low as possible. Thus, the level of impurities should not exceed 75% of the value of the level of the catalyst, for example, no greater than 70 percent of that of the catalyst level used (for example, 70 percent of 0.1 mole equivalent) . Preferably the level of impuries is no more than 25% of the level of the catalyst and most preferably is no greater than 1% of the amount of the catalyst. Examples of impurities that could interfere with this reaction include, but are not limited to, carboxylic acids, alcohols and water. This restriction forces the conditions of the reaction to be essentially free of water and the starting ester to be free of unreacted alcohol, acid and water. Some of the catalysts useful in this invention may be quite hygroscopic (for example, DMF) and must be dried before use.

In particular embodiments of this invention the following groups of compounds are of interest. A particular compound of interest is N- (3,5,5- trimethylhexanoyl) - -aminohexanoic acid and sodium and ammonium salts thereof. EXAMPLES

The following examples are illustrative of the invention but should not be construed as limitations thereon. Unless otherwise indicated, w/w means weight/weight basis, ml means milliliter, and the chemical symbols and abbreviations have their usual and customary meanings. All temperatures are in degrees Centigrade.

Example 1 N- (3.5.5-trimethγlhexanoγl) -6-aminohexanoic acid

Into a dry glass reactor were added 3,5,5- trimethylhexanoic acid methyl ester (50 g, 0.291 moles) , caprolactam (32.8 g, 0.291 moles) and dimethylformamide (2.1 g, .029 moles) . The mixture was heated to 100 degrees C and potassium tert-butoxide (3.9 g, 0.035 moles) was added all at once. There was observed an immediate color change to a red-brown. The reaction was stirred gently for about 1 hour during which the reaction medium turned opaque and more viscous. Then water (80 g, about 20 degrees C) was added and NaOH (23 g of 50% (w/w) aqueous solution, 0.291 moles) was added. After stirring vigorously for 30 minutes at 100 degrees C, the reaction was hazy but single phase. This was acidified with addition of aqueous HCl to pH 2. The products separated as a floating oil and was washed twice with 50 ml aliquats of fresh water. The product separated as a waxy solid (at room temperature) on top of the aqueous layer and was isolated (83 g, 102%) . The structure of the product was verified by carbon and hydrogen NMR and infrared spectroscopy.

Example 2 N- (n-octadecoγl) -6-aminohexanoic acid methvl ester

Into a dry glass reactor was added octadecanoic acid methyl ester (29.8 g, 0.10 moles) , caprolactam (11.3 g, 0.1 moles) and dimethylformamide (15 g, 0.029 moles) . The mixture was heated to 100 degrees C and potassium tert-butoxide (3.9 g, 0.035 moles) was added. There was observed an immediate color change to a red-brown. The reaction was stirred gently for about 1 hour during which the reaction medium turned opaque and more viscous. The structure of the product was verified by carbon and hydrogen NMR and infrared spectroscopy.

Example 3 (N.N' -teraphthalamidoyl) -bis- (6-hexanoιc acid) dimethyl ester

Into a dry glass reactor was added dimethyltera- phthalate (10.0 g, 0.51 moles) , caprolactam (11.65 g, 0.103 moles) and dimethylformamide (20g, 0.04 moles) . The mixture was heated to 150 decrees C and potassium tert-butoxide (1.14 g, 0.01 moles) was added. There was observed an immediate color change to a red-brown. The reaction was stirred gently for about 1 hour during which the reaction medium turned opaque and more viscous. The structure of the product was verified by carbon and hydrogen NMR and infrared spectroscopy.

Example 4 Comparative Example

The following example was performed using the information described in German Patent Number 1,184,769.

Methyl isononanoate (86 g, 0.5 mole) and caprolactam (56.6 g, 0.5 mole) were charged to a reaction vessel and heated to 180 degrees C for 23 hours. Analysis of the product showed 90% recovered starting materials and less than 10% conversation to the desired N- '3,5,5- trimethylhexanoyl) -6-aminohexanoic acid methyl ester.

Claims

What is claimed is:

1. A method for synthesizing a compound of Formula I:

(R¹CONHR²COOM_x M^*x

Formula I where:

R^: is selected from the group consisting of C_j. - C₁₀₀ straight or branched chain alkyls and alkenylε and benzyl optionally substituted by one or two members selected from the group consisting of C_- C._ alkyl and alkenyl, and wherein the R¹ group may optionally be substituted with a member of the group consisting of fluorine, chlorine, bromine, iodine, -OR³⁰, -C(0)OR³¹, NH₂,

0 1 0

^■P — OR³' 1

— P— OR⁴⁰ — P— 0R^{4 i} -P— OR⁴⁴ 1

0 R^{4 ;} OR^{4 1} o 1"-

where R³⁰ - R⁵⁰ are each selected independently from the group consisting of C_ - C₁₀₀ straight or branched chain alkyls and alkenyls, and benzyl optionally substituted by one or two members selected from the group consisting of C₁-C_ιs alkyl and alkenyl;

R² is selected from the group consisting of C₂ - C-₂₃ straight and branched chain alkylenes and alkenylenes, wherein R² is optionally substituted with a member of the group defined for substitutions for R¹,-

M is selected from the group consisting of hydrogen, alkali metal cations, alkaline earth metal cations, and ammonium cation; and x = 1 or 2 and is selected to satisfy the valence requirements of M; wherein said method comprises the steps of :

(a) esterifying as acid of Formula II: R^ι -

COOH, wherein R¹⁰ has the same definition as R^l, with an alcohol of Formula III: R^:j-OH, wherein R^2η has the same definition as R¹;

13 (b) reacting said ester with a lactam of Formula V:

Formula V

in a ratio of from about 1:100 to about 100:1 of ester to lactam;

(c) heating said mixture to a temperature in the range of about 40 to about 250 degrees C;

(d) adding a catalyst selected from the group consisting of first component selected from the group consisting of:

(i) an alkali metal alkoxide formed from the alkali metal salts of straight chain or branched C_; - C_1Q alcohols; (ii) metallated amines of Formula VI:

Q-N(R³) (R⁴) , wherein Q is selected from the group consisting of Group I and Group II metals, and R^! and R⁴ may be the same or different and are each independently selected from the group consisting of hydrogen and - C₆ alkyls; and (iii) basic catalysts whose conjugate acid has a pKa greater than about 16, selected from the group consisting of metallated alkyls having 1-6 carbons wherein the metal portion is selected from the group consisting of lithium, sodium and magnesium, and alkyl magnesium halides wherein the alkyl portion has from 1-6 carbons; and

(e) continuing the heating until the reaction is complete and a compound of Formula VII is present :

R^:-C(0) -N(H) -R²-COOR²⁰

Formula VII

wherein R² has the same definition as R-; and (f; reacting the compound of Formula VII to form a compound of Formula I .

2. The method of Claim 1 wherein R¹ is selected from the group consisting of C₅ - C₅₀ alkyls and alkenyls.

3. The method of Claim 2 wherein R^L is selected from the group consisting of C₇ - C₂₀ alkyls and alkenyls.

4. The method of Claim 1 wherein R² is selected from the group consisting of are C₂ - C₂₀ alkylenes and alkenylenes.

5. The method of Claim 4 wherein R² is selected from the group consisting of C₂ - C₁₀ alkylenes and alkenylenes .

6. The method of Claim 1 wherein M is selected from the group consisting of sodium, potassium, lithium, calcium, magnesium, monoethanol ammonium, a ethanol ammonium and triethanol ammonium.

7. The method of Claim 1 wherein R^2" is selected from the group consisting of C_: - C_IC alkyl.

8. The method of Claim 7 wherein R^2' is selected from the group consisting of C. - C alkyl.

9. The method of Claim 1 wherein said ratio of ester to lactam is from 1:20 to 20:1.

10. The method of Claim 9 wherein said ratio of ester to lactam is about 1:1.

11. The method of Claim 1 wherein said first component of said catalyst is selected from the group consisting of sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, sodium tert- butoxide, potassium methoxide, potassium ethoxide, potassium propoxide, potassium butoxide, potassium tert-butoxide, lithium methoxide, lithium ethoxide, lithium propoxide, lithium butoxide and lithium tert-butoxide.

12. The method of Claim 11 wherein said first component of said catalyst system is potassium tert-butoxide.

13. The method of Claim 1 wherein the catalyst comprises a second component selected from the group consisting of an acylation catalyst selected from the group consisting of dimethylformamide, pyridine, N, -dimethylaminopyridine, dimethylsulfoxide, dimethoxyethane, 18-crown-6, hexamethyl- phosphortriamide, tetrahydrofuran and dietnyl ether.

14. The method of Claim 13 wherein said second component of the catalyst is dimethylformamide.

15. The method of Claim 13 wherein the amount of each of said first component and said second component of said catalyst is independently selected from the range of about 0.001 - 35.0 mole equivalents.

16. The method of Claim 15 wherein said range is from about 0.001 - 3.0 mole equivalents.

17. The method of Claim 16 wherein said range is from about 0.01 - 1.0 mole equivalents.

18. The method of Claim 17 wherein said range is from about 0.05 - 0.50 mole equivalents.

19. A method for synthesizing a compound of Formula VII:

R^CIO, -N(H) -R²-COOR²

Formula VII

where :

R¹ is selected from the group consisting of C_: - C_ι:;ι; straight or branched chain alkyls and alkenyls and benzyl optionally substituted by one or two members selected from the group consisting of C^C^ alkyl and alkenyl, and wherein the R¹ group may optionally be substituted with a member of the group consisting of fluorine, chlorine, bromine, iodine, - OR³⁰, -C(0)OR³¹, NH,,

0 — N-R 0 R³⁷

— N— R³⁵ I I /

-C -R , 1 — c- -N

R ³⁶

OR⁴⁴

o o

-S-R- —S-R^{* «} —S-OR⁴

o o

—0—S-OR⁵⁰ ,

where R³⁰ - R⁵⁰ are each selected independently from the group consisting of C_x - C₁₀₀ straight or branched chain alkyls and alkenyls, and benzyl optionally substituted by one or two members selected from the group consisting of C-_^-C^ alkyl and alkenyl; R² is selected from the group consisting of C₂ - C₂₀ straight and branched chain alkylenes and alkenylenes, wherein R² is optionally substituted with a member of the group defined for substitutions for R¹,-

R²⁰ has the same definition as R¹; wherein said method comprises the steps of:

(a) esterifying as acid of Formula II: R¹⁰-CCOH, wherein R¹⁰ has the same definition as R^: , with an alcohol of Formula III: R²⁰-OH, wherein R²⁰ has the same definition as R ;

(b) reacting said ester with a lactam of Formula V:

Formula V

in a ratio of from about 1:100 to about 100:1 of ester to lactam; (c) heating said mixture to a temperature in the range of about 40 to about 250 degrees C; (d) adding a catalyst selected from the group consisting of a first component selected from the group consisting of:

(i) an alkali metal alkoxide formed from the alkali metal salts of straight chain or branched C_ - C₁₀ alcohols; (ii) metallated amines of Formula VI:

Q-N(R³) (R⁴) , wherein Q is selected from the group consisting of hydrogen, C_x - C₆ alkyls, phenyl, benzyl and cyclehexyl, and R³ and R⁴ may be the same or different and are each independently selected from the group consisting of hydrogen and - C₆ alkyls; and (iii) basic catalysts whose conjugate acid has a pKa greater than about 16, selected from the group consisting of metallated alkyls having 1-6 carbons wherein the metal portion is selected from the group consisting of lithium, sodium and magnesium, and alkyl magnesium halides wherein the alkyl portion has from 1-6 carbons; and (e) continuing the heating until the reaction is complete and a compound of Formula VII is present .

20. The method of Claim 1 comprising the further steps of:

(a) adding sufficient water to the compound formed in Claim 1 to produce an aqueous slurry or emulsion of about 10 - 70 percent organic content ; and

(b) adding from about 0.2 - 10.0 mole equivalents of a base selected from the group consisting of NaOK, KOH, Ca(OH)₂, tributylamine, dicyclohexylamine, monoethanolamine, diethanolamine, triethanolamine, diisopropylamine, isopropanolamine, and mixtures thereof,-

(c) heating the mixture to distill off the water and remove the hydrolyzed alcohol;

(d) adding water at about the same rate at which is being distilled off; and

(e) maintaining the viscosity of the reaction at a value at which it can be stirred.

21. The method of Claim 20 comprising the further step of lowering the water content of the product produced by the method of Claim 20 so that the active content is increased to a value between 10 and 100 percent while maintaining a liquid which is pourable at room temperature.

22. A compound of Formula VII:

R^x-C(0) -N(H) -R²-COOR²⁰

Formula VII

where :

R¹ is selected from the group consisting of C_ - C₁₀₀ straight or branched chain alkyls and alkenyls and benzyl optionally substituted by one or two members selected from the group consisting of C^C-^ alkyl and alkenyl, and wherein the R¹ group may optionally be substituted with a member of the group consisting of fluorine, chlorine, bromine, iodine, - OR³=, -C(0)OR³¹, NH₂,

0

0 — N-R 0 R³⁷

H 3, — N— R³⁵ II /

-C -R , — C- - N

R 1 ³⁶ V

O

I 0 O

-S-R ^' — - Ss-— v \_/ R^" , —S-R⁴' , — S— O _nR_n ⁴«<⁵ ,

— O— S-OR⁵⁰ ,

where R³⁰ - R⁵⁰ are each selected independently from the group consisting of C_ - C₁₀₀ straight or branched chain alkyls and alkenyls, and benzyl optionally substituted by one or two members selected from the group consisting of C,-C_1S alkyl and alkenyl;

R² is selected from the group consisting of C₂ - C₂₀ straight and branched chain alkylenes and alkenylenes, wherein R² is optionally substituted with a member of the group defined for substitutions for R¹; and

R²⁰ has the same definition as R¹

23. A compound of Formula VII which is (N,N'- teraphthalamidoyl) -bis- (6-hexanoic acid) dimethyl ester.

24. The method of Claim 1 wherein Q is selected from the group consisting of sodium, lithium and magnesium.