FI73897C - FOERFARANDE FOER GENOMFOERANDE AV REAKTIONER I SILIKONOLJA. - Google Patents

Description

73897

This invention relates to a process for carrying out organic reactions in silicone oil.

5 The carrying out of organic reactions in organic solvents is well known. The most important solvents are aliphatic and aromatic hydrocarbons as well as the corresponding alcohols, some ketones, ethers, esters and short-chain chlorinated hydrocarbons. Crucial to which solvent is selected as the reaction medium is the solubility of the reactants in that Liu solvent. In addition, the volatility, flammability and evaporation rate of the solvent are important considerations in the choice of the solvent as the reaction medium. In almost all cases, the choice of solvent 15 as the reaction medium still depends on the extent to which it reacts with the reaction components or reaction products.

Furthermore, it is known that many organic reactions take place in the above-mentioned solvents only in unsaturated yields or in such a way that impure end products are formed. Therefore, there was a need to find a reaction medium for carrying out organic reactions which has a good solubility for the reactants or the desired end product and in which the desired reactions can be carried out with little or no side reactions and as pure end products as possible. In such solvents, the reactions should be as simple as possible and the reactions should be feasible without high equipment costs.

The method of the present invention satisfies the above conditions.

The invention relates to a process for carrying out reactions between a) alkyl halides and amines, or b) alkyl halides. and alcohols, alcoholates or mercaptans, or c) amines and sulfonic acids or sulfonic acid chlorides to form organic ammonium salts, and or d) amines and compounds having a methoxy or ethoxy group in the <= <position to the unsaturated group. - 5 den, or e) between amines and aromatic carboxylic acid esters whose ester moiety contains 1 to 4 carbon atoms to form the corresponding acid amides, or f) between secondary amines and chloroacetals.

The process is characterized in that the reaction components are reacted with one another in a silicone oil having a viscosity of 40-20,000 mm 2 / s (cSt) at 25 ° C.

The process according to the invention is suitable, inter alia, for reactions in which amines react with esters, alkoxy compounds or alkyl halides, such as, for example, condensation reactions or substitution reactions of those in which hydrogen halide, in particular hydrogen chloride, is liberated. Reaction of amines, especially tertiary amines, with alkyl halides results in the formation of quaternary ammonium salts. The reactants are, on the one hand, alkyl halides, the alkyl groups of which may be substituted by functional groups which do not react with siloxanes, and, on the other hand, either amines, alcohols or alcoholates or also mercaptans.

In general, the substitution reactions take place according to reaction schemes (I) and (II), R'Cl + R2N-R "-> R'-Ä -R" Cl "(I) RR 30 R'Cl + MZ-R" -> R'-ZR "+ MCI (II) (M-alkali metal) wherein R 'is alkyl preferably having 1 to 8 carbon atoms, or phenyl, R is hydrogen or a C 1-4 alkyl group, R" is H or 35 R 'and Z are oxygen or sulfur. Cl can also be replaced by Br or I.

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Instead of an alkyl halide, chloroacetal can also be reacted with an amine, preferably a secondary amine. In this case, the amine is used to scavenge the excess hydrogen chloride released.

When preparing compounds according to these reaction schemes, carrying out the preparation in siloxanes has the advantage of obtaining products in high yields in the highest yields. In carrying out the preparation, the yields used in the solvents used so far are lower and the reaction products obtained are not so pure. Examples of compounds that can be prepared in this manner include oxirane-methylamine-N, N, N-trimethyl chloride (1/1 sidyltrimethylammonium chloride), tetrabutylammonium bromide and benzyltriethylammonium bromide.

However, aromatic sulfonic acids and sulfonic acid chlorides which can be reacted with amines according to the invention are also suitable as starting materials for the preparation of organic ammonium salts. The aromatic backbone may then be substituted by an alkyl group or halogen. In this case, it is possible to prepare both sulfonamic acids and tertiary ammonium salts. In this connection, the process according to the invention has the advantage that in siloxane the desired reaction product precipitates as a solid and can thus be easily separated from the other reaction components.

Suitable starting materials for the reaction of amines with compounds containing a methoxy or ethoxy group in the -X position relative to the unsaturated group include, for example, methoxymethylenemalonic acid methyl ester and ethoxymethylene malonic diethyl ester.

When amines react with carboxylic acid esters, the carboxylic acid ester is an aromatic ester having an ester moiety of 1 to 4 carbon atoms. Amine can then also be used as ammonia. Products that can be prepared in this manner include, for example, benzoic acid methylamide (from benzoic acid esters and monomethylamine) and toluylamide (from toluyl ester and ammonia).

4 73897

The process according to the invention, in which siloxanes are used as the reaction medium, further makes it possible to carry out phase transfer reactions in which the second phase is mainly the aqueous phase. However, the second phase can also be another organic solvent which is immiscible with the siloxanes.

In the event that one of the reactants is insoluble in the silicone oil, this can either be melted and added in the molten state to the silicone oil or added to the silicone-10 dissolved in an organic solvent. The spent organic solvent can then be distilled off.

The siloxanes used in the process of the invention are dimethylsiloxane-based oligomers and polymers which may have both an annular and a chain structure. Branches are also possible. They must not react with alkyl or aryl halides and, if possible, must not contain functional groups. In addition, they should be liquid at room temperature and, if possible, up to a temperature of about 200 ° C, preferably 20 to 100 ° C. The siloxane or silicone oils used have a viscosity at 25 ° C of about 40 to 200000 cSt, preferably 50 to 2000 cSt. Most of the compounds listed below meet these conditions.

Useful silicone oils include, in particular, compounds containing structural units of the formula -Si -ΟΟ X2 wherein X is an alkyl group having 1 to 4 carbon atoms, preferably a methyl group, or a phenyl group. Preferably, compounds are used in which at least one of the two X groups is a phenyl group. Examples of compounds of this formula are hexamethyldisiloxane, hexaethyl-35-lydisiloxane, hexakis (2-ethylbutoxy) disiloxane, 1,3-dimethyl-1,3-diphenyldidiloxane, 1,1,3,3-tetraphenyl-1,3-dimethyldisiloxane, 1 , 1,5,5-tetraphenyl-1,3,3,5-5,7897 tetramethyltrisiloxane, 1,1,3,5,5-pentaphenyl-1,3,5-trimethyltrisiloxane, polydimethylsiloxane, polydimethyldiphenylsiloxane, polymethylphenyldiphenyldiside oxane and polydiphenylsiloxane. The end groups of the polymers are preferably trimethylsiloxy groups.

Examples of silicone oils having a ring structure are hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and hexaphenylcyclotrisiloxane.

Alkyltrialkoxysilanes whose ester groups are completely substituted by trialkylsilyl groups (alkyl groups contain 1 to 4 carbon atoms) can also be used as reaction media according to the invention. Such compounds and their preparation are described, for example, in DE-15 2,642,833. Tetrakis (trialkylsiloxy) silanes ("Schweizerkreutz") can also be used in the process according to the invention. These compounds can be understood as orthosilicic acid esters in which the alkyl groups contained in the ester groups have been replaced by trialkylsilyl groups.

Example 1 94.9 g (= 1.026 mol) of epichlorohydrin were dissolved in 450 ml of hexamethyldisiloxane. 59 g (= 1 mol) of trimethylamine were introduced into the solution via a gas line over a period of 2.5 h. As early as 1 h, the desired oxiranemethylamine Ν, Ν, Ν-trimethyl chloride precipitated as a solid; no increase in temperature occurred, but the reaction temperature was 20-25 ° C throughout the reaction.

After 24 h, the solid was filtered off using a dense filter, washed with hexamethyldisiloxane and then methyl ethyl ketone and then dried in vacuo.

The epoxide content of the dried product was about 93-94%. 35 mol of epichlorohydrin were added to the mother liquor, and 59 g of trimethylamine were again introduced into this solution.

After 24 h, the precipitated final product was separated and treated as described above. The purity of the solid obtained was again 93-94%.

Example 2 138.7 g of epichlorohydrin were dissolved or suspended in 378 g of polydimethylsiloxane having a viscosity of 50 cst at 25 ° C. 59 g of trimethylamine were then introduced. The epichlorohydrin was completely dissolved in the polydimethylsiloxane during the introduction of the amine, and after 20 min the first oxirane-10 methylamine-N, N, N-trimethyl chloride crystals formed. After 24 h, the resulting solid was filtered off and treated as in Example 1 with the exception that it was first washed with polydimethylsiloxane.

The mother liquor was treated in the same manner. Even then, the first 15 crystals formed after 20 min.

After 24 h, the precipitate was again filtered off and treated as described above. Its purification rate was 92-93%. The yield was 55%, based on the amount of trimethylamine used.

The remaining mother liquor was further treated in the same manner as the mother liquor from the first batch. It resulted in a final product of the same degree of purity; however, the yield, calculated from the amount of trimethylamine, was 72%.

Example 3 The procedure was the same as in Examples 1 and 2, but using polymethylphenylsiloxane as the silicone oil. Treatment of the precipitate formed in the first reaction gave a yield of 37.4%, based on the amount of trimethylamine, with a purity of the product of 93-95%.

Treatment of the mother liquor of this first reaction gave a yield of 92%, based on the amount of trimethylamine used.

Example 4

Preparation of Tetrabutylammonium Bromide The preparation of this compound is described, for example

II

U.S. Patent No. 3,735,178 to 7,738,897, which uses acrylonitrile as the solvent to give yields in excess of 50%. However, working with acrylonitrile requires considerable safety measures that make the process uneconomical. To avoid these disadvantages, it has already been proposed to carry out the reaction in higher alcohols, esters or concretes.

However, only about 50% yields were obtained, which required reaction times of about 48 h.

According to the invention, 186 g (= 1 mol) of tributylamine were dissolved in 1000 g of polydimethylsiloxane having a viscosity of 50 cSt. To this solution was added 1 mol (1 = 137 g) of butyl bromide, which was slightly colored. The mixture was gently refluxed to initiate the reaction and allowed to react at 150-155 ° C for 20 h. The remaining volatile constituents were then separated under reduced pressure.

The resulting reaction mixture was cooled, and water was added to the resulting crystalline slurry containing 20 substances. The lower solution containing tetrabutylammonium bromide was separated and the color present was removed by washing with toluene. Evaporation of the remaining aqueous solution gave 234.5 g of a pure white final product with a purity of 99.5 to 100% as determined on a Br basis.

The yield was 72.6%.

Example 5

Preparation of benzyltriethylammonium chloride 200 g of the polydimethylsiloxane 30 of Example 4 were dissolved in 101 g (= 1 mol) of triethylamine. To this solution was stirred 137 g (= 1 mol) of benzyl chloride.

After 5 h (reaction temperature 80 ° C) a large amount of solid had already formed, which was separated by filtration and washed with methyl ethyl ketone.

After drying, 174 g of benzyltriethylammonium chloride with a purity of 99.4 to 99.5% were obtained.

The yield was about 76.3%.

β 73897

Example 6 600 g of methylphenylpolysiloxane available under the tradename Siliconöl PD-5 (manufactured by Bayer AG, Leverkusen}) were mixed under a nitrogen atmosphere with 216.4 g (= 1 mol) of ethoxymethylenemalonic acid diethyl ester 5 and 108 g; with 6-methyl-2-aminopyridine, the aminopyridine was then in a molten state where it dissolves in silicone oil, and the mixture was maintained at 90 to 100 ° C, and the alcohol formed in the reaction was distilled off under very low pressure. no distillation was observed, the reaction medium was cooled to 60 ° C.

In the cooled silicone oil, the desired methyl-pyridylaminomethylenemalonic acid diethyl ester precipitated as crystals, which were separated by filtration, washed at 20 ° C and dried. The yield of the product thus obtained with a purity of 99% was 316 g (= 96.9%).

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Claims (8)

73897 A process for carrying out reactions a) between alkyl halides and amines, or 5 b) between alkyl halides and alcohols, alcoholates or mercaptans, or c) between amines and sulphonic acids or sulphonic acid chlorides to form organic ammonium salts, or 10 d) between amines and compounds having a methoxy or ethoxy group at the et position relative to the unsaturated group, or e) between amines and aromatic carboxylic acid esters having an ester moiety of 1 to 4 carbon atoms to form the corresponding acid amides, or f) secondary amines and chloroacetals. characterized in that the reaction components are reacted with one another in a silicone oil having a viscosity of 20 to 40,000 mm 2 / s (cSt) at 25 ° C. Process according to Claim 1, characterized in that the silicone oil used is an oligomeric or polymeric alkyl or arylsiloxane containing structural units of the formula -Si-O-X 2 in which X is an alkyl or phenyl group. Process according to Claim 1, characterized in that a silicic acid ester substituted by silyl groups is used as the silicone oil. Process according to one of Claims 1 to 3, characterized in that the reacting compound is an amine. 10 73897 Process according to one of Claims 1 to 4, characterized in that the amine is reacted with an alkoxy compound. Process according to one of Claims 1 to 4, characterized in that the amine is reacted with an alkyl halide. Process according to one of Claims 1 to 3, characterized in that alkyl halides and alcoholates are used as reaction components. Process according to one of Claims 1 to 7, characterized in that the separation of the reaction product or products is carried out with the aid of a solvent insoluble in silicone oil. Il 11 73897