DE1197468B - Process for the preparation of bromine derivatives of diphenyl, diphenyl ether or di-, tri- or tetraphenyl methane with 4 or more bromine atoms per molecule - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German: 12 q-14/04

Number: 1197 468

File number: C 29807IV b / 12 q

Filing date: April 30, 1963

Opening day: July 29, 1965

In the patent application C 28110IV b / 12q (German Auslegeschrift 1 193 510) a method for Production of bromo derivatives of diphenyl, diphenyl ether or di-, tri- or tetraphenyl methane with 4 or more bromine atoms per molecule by reacting at least partially in a solvent dissolved diphenyls, diphenyl ethers or di-, tri- or tetraphenylmethane in the presence of small amounts of a halogenation catalyst and optionally water at room temperature or suggested elevated temperature, optionally with the addition of chlorine, with bromine. This method of the earlier patent is characterized in that the bromination is carried out in the presence of olefin dibromides, especially ethylene or propylene dibromide performs as a solvent and after Termination of the bromination in the reaction mixture olefins, especially ethylene or propylene, in one introduces such an amount that it corresponds to the excess bromine present in the reaction mixture at least are equimolar.

It has now been found that this method can be carried out with equally good success, if the olefin dibromides used as solvents are wholly or partially replaced by other olefin dihalides, especially ethylene, propylene or butylene dichloride or chlorobromide.

According to the process of the invention, chlorine-containing olefin dihalides, for example ethylene, Propylene, butylene or isobutylene dichloride or chlorobromide, or fluorine-containing olefin dihalides, such as l-fluoro-2,3-dibromopropane, alone or in a mixture with one another and with the corresponding Oleindibromiden used as a solvent for the aromatic compounds to be brominated will. It is essential for the successful implementation of the method according to the invention that the aromatic compounds to be brominated completely or partially in the solvents used are soluble.

The halogenation catalyst used is, for example, iron or aluminum powder or theirs Salts and / or iodine.

The amount of olefin dihalide to be used depends primarily on the solubility of the aromatic compound to be brominated in the solvent and on the viscosity of the reaction mixture during the bromination. The bromination mixture should remain easily stirrable during the bromination in order to ensure good distribution of the reactants. The olefin dihalides to be used most advantageously in each case and their processes for the preparation of bromine derivatives
of diphenyl, diphenyl ether or di-, tri-
or tetraphenylmethane with 4 and more
Bromine atoms per molecule

Addition to registration: C 28110IV b / 12 q -
Interpretation document 1193 510

Applicant:

Chemical factory Kalk G. m. B. H.,

Cologne-Kalk, Kalker Hauptstr. 22nd

Named as inventor:

Dr. Herbert Jenkner, Cologne-Deutz

Quantities can be determined by simple preliminary tests, taking into account the criteria given above can be easily determined.

In this mixture are now at normal or elevated temperature, preferably at a Temperature between 10 and 60 ° C, and with stirring the calculated amount of bromine and an excess of 0.1 to 10.0 percent by weight initiated. If there is an oxidation of the resulting during the bromination If hydrogen bromide is possible in the reaction vessel, the calculated amount of bromine is 1 gram atom Bromine per gram atom of the hydrogen to be substituted. When the oxidation of the resulting hydrogen bromide takes place outside the reaction vessel, per gram atom of the substance to be substituted Hydrogen 2 gram atom of bromine is used as the calculated amount of bromine.

In most cases, however, it is possible to use the hydrogen bromide formed during the bromination to oxidize by chlorine, which at the same time with the bromine in the reaction mixture and / or is introduced into the gas space above. Implementation is particularly easy with BrCl can be carried out, as this compound is achieved by simply mixing bromine and chlorine easily and no separate dosing of the two halogens is necessary. The reaction mixture can initially only supply a small part of the total amount of chlorine required with the bromine while the remaining amount of chlorine is only added when the entire amount has already been added

509 628/388

3 4

Contains brommage. It is useful in the very good for making combustible ones flame resistant

Reaction mixture during the process of office plastics, especially polyethylene. The her-

There is always a small excess of bromine compared to products that can be compared to highly viscous liquids the amount of chlorine supplied. Only particularly suitable for incorporation into plastics

after the end of the bromination, as much as 5 should be reduced together with antimony trioxide or

Chlorine can be added that the molar ratio of other compounds known for this purpose

of the total amount of bromine and chlorine introduced, the flammability of such plastics is considerable,

is about 1. Compared to other known methods, according to

The in the reaction mixture or in the above which the aromatic compounds are also in

chlorine introduced into the gas space causes io solvents to be brominated, the invention

not only a rapid oxidation of the bromination during the proper process the advantage

Bromination of the resulting hydrogen bromide to free after rapid onset very quickly and completely

Bromine, which runs again on the aromatic to be brominated. In the method according to the invention can

Compound acts, but it also activates the reaction mixture immediately after the end of the

the course of the bromination evidently be worked up by formation of 15 bromination, while in the

of chlorine-bromine compounds or by atomically carrying out the bromination of aromatic

Bromine, which in the oxidation of hydrogen bromide compounds in other solvents, for example

arises. wise carbon tetrachloride, always adhering to a

After the end of the bromination, a post-reaction time is required. But especially Reaction mixture one of the bromine contained therein can be the bromine derivatives according to the method of Excess of at least an equimolar amount of an olefin of the invention having an extremely low bromine over or above Olefin mixtures, especially ethylene or propylene, are shot and are free from toxic initiated. The olefin, especially the ethylene or active and strongly smelling impurities. Propylene or a mixture of olefins settles with the The viscous end products can only excess bromine to the corresponding di- 25 a small proportion of lower brominated products bromides around. It is also possible to contain in place of the, according to known methods, for. B. by Olefins their mixtures with inert gases to fractional distillation in vacuo or turning. An excess of olefin interferes with recrystallization from suitable solvents, waste of use the solvent does not. can be removed. This will make the pure ones

The reaction mixture is worked up 3 ° higher brominated products are obtained in crystalline form,
in such a way that the reaction mixture is first washed acid-free bromination of the aromatics mentioned using chlorine and / or fluorine with water or with aqueous sodium carbonate-containing olefin dihalides as a solvent for the ammonia solution or the like. After separating the aqueous olefin dibromide for the same from the organic layer, this with the purpose also becomes a technical advantage. With the usual desiccants, such as silica gel, fuller's earth, distillative removal of olefin dibromides, dried. The desiccant, for example, ethylene dibromide is expediently separated off from the resultant by filtration. Then the brominated product must be applied towards the end of the distillation solvent and the bromine derivative of diphenyl a high vacuum. By the or diphenyl ethers or di-, tri- or tetraphenyl- 40 strong cooling of the abmethans from the distillation still separated by distillation. drawing vapors in the cooler separate there

The brominated products fall off as solid substances, olefin dibromides, easily as crystalline substances. or liquids whose viscosity is so high. This disadvantage occurs when using chlorine can that they hardly and / or not fluorine-containing olefin dihalides at room temperature flow. The bromine content of the according to method 45, since they have a lower melting point than that The products that can be prepared according to the invention reside in each corresponding olefin dibromide. Even in the case of olefins close to the theoretical value. It amounts to two dihalides, which in addition to chlorine or fluorine are still for example in the case of the Er bromine contained in the process, this technical advantage is already present finding producible pentabromodiphenyl ether 69 to given. This leaves the technical advantage of the 70.5 percent by weight and obtained in the pentabromodi 50 process of the invention even if phenyl 71 to 72.5 percent by weight. The above for the bromination of the aromatic compounds Small amounts of the solvent described in the discontinuous procedure are rehalogenated drive the invention can be made with a suitable, especially since it has been shown that with repeated Design of the devices also continuously through use of the circulating solvent be guided. 55 its content of unhalogenated products almost

If the bromination remains constant in the presence of chlorine,
carried out, the brominated end products can be ο ie 1
Contain small amounts of aromatically bound chlorine. However, this chlorine content does not exceed 280 parts by weight of diphenyl ether in 415 Ge-3 percent by weight and remains dissolved in most ^6o parts by weight of 1,2-dichloroethane and in the cases obtained below 1 percent by weight. After the solution, 0.4 parts by weight of iron powder are added. Products prepared in the process of the invention for the mixture are then placed in the course of 2 hours of flame-proofing of flammable plastics, 700 parts by weight of bromine and 300 parts by weight of chlorine, this chlorine content does not interfere because it is introduced without, whereby in the reaction mixture an influence on the effectiveness of the brominated products 65 temperature of 20 to 55 ° C is maintained, and no damage to the flame-proofed After completion of the bromination is caused in the plastics. Like the chlorine-containing bromine reaction mixture, the excess bromine present through mated products is also suitable for the introduction of bound ethylene without chlorine. After that

The reaction mixture has been filtered, washed free of acid and dried, it becomes the solvent distilled off and reused as a solvent.

880 parts by weight of pentabromodiphenyl ether with a bromine content of 880 parts by weight remain as the end product 70.4 percent by weight and a chlorine content of 1.0 percent by weight as light yellow, very viscous and almost odorless liquid that is under a pressure of 0.1 mm of mercury at a temperature boils from 195 to 205 ° C.

Claims (1)

Claim: Process for the preparation of bromine derivatives of diphenyls, diphenyl ethers or di-, tri- or tetraphenylmethane with 4 or more bromine atoms per molecule by reacting the diphenyl, Diphenyl ether or di-, tri- or tetraphenyl methane in the presence of small amounts of one Halogenation catalyst and optionally water at room temperature or elevated temperature, optionally with the addition of chlorine, with bromine in the presence of olefin dibromides, especially Ethylene or propylene dibromide, as a solvent and introduction of olefins, especially Ethylene or propylene, in the reaction mixture after the bromination in such an amount that it is at least equimolar to the excess bromine present in the reaction mixture, according to the patent application C 28110 IVb / 12q (German Auslegeschrift 1 193 510), characterized in that they are used as solvents Oleindibromide wholly or partially by other olefin dihalides, especially ethylene, propylene or butylene dichloride or chlorobromide. 509 628/388 7.65 © Bundesdruckerei Berlin