CS273841B1 - Method of (2,2) paracyclophane and its derivatives production - Google Patents

Abstract

A method of production of (2,2)paracyclophane and its derivatives of general formula I, where X is an atom of hydrogen, halogen, alkyl with 1 to 4 carbon atoms or benzyl and n is 1 to 4, by thermal cleaving of (4-methylbenzyl)-trialkylammonium hydroxide or its derivatives substituted to aromatic cores of formula II, where R is alkyl with 1 to 4 carbon atoms, X and n have the abovementioned meaning, in a reaction mixture formed of inert hydrocarbon solvent and an aqueous solution of hydroxide of alkaline metals, based on the fact that the thermal decomposition occurs in the presence of alkaline sulphite. (2,2)Paracyclophane and its derivatives are used for preparation of poly-p-xylylenes. These polymers are used for creation of protective coatings in electronics, optics and medicine.<IMAGE>

Description

The invention relates to a process for the preparation of (2,2) paracyclophan and its derivatives of the general formula I, wherein X is a halogen atom, an alkyl or an alkylaryl and n is 1 to 4.

(2,2) paracyclophane and its derivatives, such as dichloro- (2,2) paracyclophane, tetrachloro- (2,2) paracyclophane, dibromo- (2,2) paracyclophane, are known compounds generally used as starting materials for the preparation of the corresponding poly-p-xylylenes. These polymers, in particular poly-p-xylylene and its chlorinated derivatives, are preferably used for the formation of protective coatings formed by the gas-phase deposition technique in vacuum, electronics, optics and medicine.

Numerous processes have been proposed for the preparation of (2,2) paracyclophan and its derivatives. In Organic Synthesos, Coli. Vol. 5, John Wiley &amp; Sons, Inc., New York, London, Sydney, Toronto, 1973, p. 003 discloses a process for the preparation of (2,2) paracyclophan by thermal decomposition of 4-methylbenzyl] trimethyl ammonium hydroxide in 17% yield.

The increase in yields (2,2) of paracyclophan prepared by thermal decomposition of (4-methylbenzyl) -trimothylainonium hydroxide was achieved by the catalytic action of copper salts (EP No. 0220 743 A1) or by decomposition in the presence of compounds of the formula CH 3 -CO-Ct 4 R is H, halogen or alkylcarboxyl (EP No. 0226 225 A2).

The highest yields (2,2) of paracyclophan were obtained when the decomposition of [4-methylbenzyl] -trimethylammonium hydroxide was carried out in the presence of dimethylsulfoxide (NSR Pat. No. 3,240,303; U.S. Patent No. 247569),

The preparation of halogenated derivatives of (2,2) paracyclophane, in particular dichloro- (2,2) paracyclophane, dibromo- (2,2) paracyclophane and tetrachloro- (2,2) paracyclophane, was carried out by chlorination and / or chlorination. bromination (2,2) of paracyclophan (US Pat. No. 3,221,068, US Pat. No. 3,200,728, US Pat.

342,754). A disadvantage of the aforementioned processes of direct halogenation (2,2) of paracyclophan is that it requires a costly substance (2,2) as a starting material (2,2). A further disadvantage of the described processes for the preparation of e.g. dichloro- (2,2) paracyclophane is the fact that the product obtained contains, in addition to dichloro- (2,2) paracyclophane, unreacted (2,2) paracyclophane, a dichloro derivative with chlorine atoms bonded to one aromatic ring and chloro derivatives with more than two chlorine atoms per molecule. Similarly, in the case of the production of tetrachloro- (2,2) paracyclophan, a reaction mixture is obtained containing a significant amount of products in which the chlorine atoms are distributed undesirably in moloc I.e and must be removed by expensive operations. The direct bromination of (2,2) paracyclophan is characterized by low yields.

With a view to obtaining a clearly defined product, processes have been developed which prepare starting materials so as to ensure the desired number and distribution of halogen atoms, respectively. other substituents in the molecule. The raw materials thus prepared are converted to the corresponding quaternary ammonium base and the desired product is obtained by topical decomposition (Nos. 246320, 248342 and 256776, EP No.0220 744 Λ1 and EP No 0226 225 Λ2). .

Of all known processes, they yield the highest yields (2,2) of paracyclophan and resp. its derivatives by processes in which the corresponding quaternary ammonium base is thermally decomposed in an alkaline medium in the presence of dimethylsulfoxide.

A disadvantage of the processes used for dimethylsulfoxide, despite the high yields achieved, is that the regeneration of dimethylsulfoxide, which is used in amounts of quantity, yeah, with the deterioration in the composition of the dimethylsulfoxide phase, is very difficult and therefore economically demanding. / paracyclophan and its derivatives less attractive in terms of production on an industrial scale. Increased demands, from an ecological point of view, are also placed on waste water treatment from processes using dimethylsulfoxide.

The above disadvantages are overcome by a process for the preparation of (2,2) paracyclophan and its derivatives by decomposition of a quaternary ammonium base of formula (II) wherein X is hydrogen, fluorine, chlorine, bromine, iodine, (C 1 -C 4) alkyl or benzyl; n is 1-4 and R is the same or different alkyl having 1 to 4 ato _t we atoms, at 40 to 140 ° C, preferably at TECS 273 041 01 fence 50 to 95 ° C in a reaction medium comprising an inert hydrocarbon solvent, with a solution alkali metal hydroxide according to the invention, characterized in that the decomposition is carried out in the presence of an alkali sulphite. The inert hydrocarbon solvent may preferably be aromatic hydrocarbons such as benzene, toluene or xylene. According to the invention, the alkyl radical R is preferably methyl or ethyl. The alkali metal hydroxide solution is preferably an aqueous solution of sodium hydroxide or potassium hydroxide. The alkaline sulphite according to the invention is preferably sodium metabisulphite and potassium sulphite.

The quaternary ammonium base II is prepared in a manner known per se from the corresponding halogenated derivative of the general formula III, wherein Y is chlorine, bromine or iodine and X and π are as defined above, by reaction with trimothylamine to form the corresponding quaternary ammonium salt of formula IV wherein X , to Y have the meaning given above, which is converted to the quaternary ammonium base II (where R is methyl) in the presence of an inorganic hydrocarbon solvent in the presence of an inorganic hydrocarbon solvent in the presence of said reaction medium, in the presence of alkali sulfite, thermally cleaved.

Alternatively, it is possible to isolate the quaternary ammonium salt IV and convert it to the quaternary ammonium base II in a known manner, by treatment with silver oxide or by treatment with a strongly basic unuxom.

An advantage of the process according to the invention is the fact that its derivatives are produced in a high yield of 80 to B5 wt.%. and (2,2) paracyclophane derivatives have a defined structure. The essential advantage of the present invention is that the process can be used on an industrial scale, eliminating the need for costly recovery of the soluble organic matter from the aqueous phase and thereby reducing the wastewater treatment requirements of the process.

The process according to the invention is best illustrated in the following examples.

Example 1

In a 6 L three-necked flask equipped with a stirrer, reflux condenser and thermometer was charged 4 L of toluene, 199 g of (4-methylbenzyl) trimethylammonium chloride dissolved in 100 mL of water, a solution of 200 g of sodium hydroxide in 200 mL of water. and 300 o anhydrous sodium sulphite. The reaction mixture was heated to 90 ° C with vigorous stirring for 30 hours. The resulting polymer was filtered from the reaction mixture and the phases separated. The organic phase was washed with water and evaporated to dryness. 85.3 g of crude product was obtained, which recrystallized to give 03.7 g, 00.5% by weight. (2,2) paracyclophan. The purity of the product determined by gas chromatography was 99.1% by weight.

Example 2

To a 10 L three necked flask equipped with stirrer, reflux condenser and thermometer was charged 6 L of toluene, 360.4 g (chloro-4-methylbenzyl) -trimethylammonium chloride (a mixture of two isomers) dissolved in 150 mL of water, 180 g NaOH in 300 ml of water and 450 g of anhydrous sodium sulphite. The reaction mixture was heated at 60 ° C for 4 hours with vigorous stirring. Further, the decomposition temperature was raised to 70 ° C and maintained for 6 hours. The reaction was complete at 90 ° C. After cooling, the polymer was filtered from the reaction mixture and the phases separated. The organic phase was washed with water and evaporated to dryness. 101.4 g of crude product were obtained, which recrystallized to give 175.2 g, i.e. 82.1% by weight. dichloro- (2,2) paracyclophan. The purity of the product determined by gas chromatography was 99.0% by weight,

Example 3

In a 6 L three necked flask was charged 140 g of 4-methylbenzyl chloride and 4 L of toluene. While stirring, 65 g of trimethylamine was added and the mixture was heated to 00 ° C for 3 hours. The resulting (4-methylbenzyl) -trimethylammonium chloride was added to the solution by addition

CS 273 041 DI1 ml of water. After addition of a solution of 200 g of sodium hydroxide in 200 ml of water or 300 g of anhydrous sodium hydroxide solution, the reaction mixture was heated to 90 ° C with vigorous stirring for 25 hours. After completion of the reaction, the resulting polymer was filtered from the reaction mixture and the fusions separated. The organic phase was washed with water and evaporated to dryness. 04.2 g of crude product was obtained, which recrystallized to give 03.3 g, i.e. 00.1 wt. (2,2) paracyclophan. The purity of the product by gas chromatography was 99.5% by weight.

Example 6

A three-necked flask of 10 ml capacity equipped with a stirrer, reflux condenser and thermometer was charged with 260 g of chloro-4-methylbenzyl chloride (a mixture of 2-chloro-4-methylbenzyl chloride and 3-chloro-4-methylbenzyl chloride isomers) of 6 L toluene. While stirring, 100 g of trimethylminine was added and the resulting mixture was heated to 00 ° C for 4 hours. The resulting (chloro-4-methylbenzyl) trimethylammonium chloride was dissolved by adding 150 ml of water. After addition of a solution of 100 g of sodium hydroxide in 300 ml of water and 450 g of anhydrous sodium sulfite, the mixture was heated to 60 ° C for 4 hours with vigorous stirring. Further, the decomposition temperature was raised to 70 ° C for 6 hours. Ronltoo was completed at toplolf 91 ° C.

After cooling the reaction mixture, the resulting polymer was filtered off with a separated phase. The organic phase was washed with water and evaporated to dryness. 160.0 g of a crude product were obtained, which were covered; It gave 164.5 p, ie 79.5 X wt. The product chromatographically determined by gas chromatography was 99.0% by weight.

Example 5

A 6 L 3-necked flask equipped with a stirrer, reflux condenser and thermometer was charged with 200 g dlchloro-4-methylbenzyl chloride (a mixture of isomers in which the chlorine atoms are attached to the aromatic nucleus at positions 2,3-, 2,5- and 2,6 -) and 4 L of toluene. While stirring, 65 Q of trimethylamine was added and the mixture was heated to 00 ° C for 6 hours. The resulting (dichloro-4-methylbenzyl) -trimothylammonium chloride was dissolved by the addition of 100 ml of water. After addition of a solution of 120 g of sodium hydroxide and 300 g of anhydrous sodium sulfite in 200 ml of water, the mixture was heated to 50 ° C for 2 hours with vigorous stirring. In addition, the decomposition temperature was raised to 60 ° C and maintained for 5 hours. Further, the decomposition was carried out at 75 ° C for 4 hours and the reaction was completed at 90 ° C. After cooling the reaction mixture, the resulting polymer was filtered off and the phases separated. The organic phase was washed with water and evaporated to dryness. 145 g of crude product were obtained, which recrystallized to give 141.2 g, i.e. 01.6% by weight. tetrachloro- (2,2) paracyclophan. The purity of the product as determined by gas chromatography was 99.1% by weight.

Example 6

In a 6 L 3-necked flask equipped with a stirrer, reflux condenser and thermometer was charged 150 g of fluoro-4-methylbenzyl chloride (a mixture of isomers in which the fluorine atoms are attached to the aromatic nucleus at 2- or 3- position) and 4 L of toluene. While stirring, 70 g of trimethylamine were added and the mixture was heated to 80 ° C for 6 hours. The resulting (fluoro-4-methylbenzyl-D-trimethylammonium chloride) was dissolved by the addition of 100 ml of water. After addition of a solution of 120 g of sodium hydroxide in 200 ml of water and 300 g of anhydrous sodium sulfite, the resulting reaction mixture was heated to 50 ° C to 90 ° C. After 40 hours the reaction mixture was cooled, the polymer formed was filtered off and the phases were separated and the organic phase was evaporated to dryness to give 96.0 g of crude product which recrystallized to give 95.12 g (79.0% by weight). The purity of the product as determined by gas chromatography was 99.2% by weight.

Example 7

To a 6 L 3-necked flask equipped with a stirrer, reflux condenser and thermometer was

CS 273 841 B1 16B g of 2-ethyl-4-methylbenzyl chloride and 4 L of toluene were added. While stirring, 70 g of trimothylamine was added and the mixture was heated to BO ° C for 6 hours. The resulting (2-ethyl-4-methylbenzyl-D-trimethylammonium chloride) was dissolved by the addition of 100 ml of water, after addition of a solution of 120 g of sodium hydroxide in 200 ml of water and 300 g of anhydrous sodium sulfite. ° C for 40 hours After completion of the reaction, the resulting mixture was cooled, the resulting polymer was filtered off and the phases separated and the organic phase was evaporated to dryness to give 95.1 g of crude product which recrystallized to give 93.7 g of diethyl-2, The purity of the product, determined by gas chromatography, was 99.0% by weight.

Example S

A 6 L 3-necked flask equipped with a stirrer, reflux condenser and thermometer was charged with 219 g of bromo-N-methylbenzyl chloride (a mixture of isomers in which bromine atoms are attached to the aromatic nucleus at 2- or 3- position) and 4 L of toluene. While stirring, 70 g of trimothylamine were added and the mixture was heated to 00 ° C for 6 hours. The resulting (bvom-4-methylbenzyltrimethylammonium chloride) was dissolved by the addition of 100 ml of water. After addition of a solution of 120 g of sodium hydroxide in 200 ml of water and 300 g of anhydrous sodium sulfite, the reaction mixture was heated gradually from 40 ° C to 90 ° C. After completion of the reaction, the resulting mixture was cooled, the resulting polymer was filtered off of the separated phases, and the organic phase was evaporated to dryness to give 139.2 g of crude product which recrystallized to give 137.3 g (75% dibromo). The purity of the product, determined by gas chromatography, was 99.1% by weight.

Example 9

To a 6 L 3-necked flask equipped with a stirrer, reflux condenser and thermometer was charged 230 g of benzyl-4-methylbenzyl chloride (mixture of isomers) and 4 L of toluene. While stirring, 70 g of trimethylamine were added and the mixture was heated to 80 ° C for 6 hours. The resulting (benzyl-4-methylbenzyl) -trimethylammonium chloride was dissolved by adding 100 ml of water. After addition of a solution of 120 g of sodium hydroxide in 200 ml of water and 300 g of anhydrous sodium sulfite, the reaction mixture was heated gradually from 40 ° C to 90 ° C for 40 hours. After the reaction was completed, the polymer was filtered off and the phases separated. The organic phase was evaporated to dryness. 135.0 g of crude product were obtained, which recrystallized to give 132.5 g (69.0% by weight) of dibenzyl- (2,2) -paracyclophan. The purity of the product, determined by gas chromatography, was 9B, 9 wt.

Claims (1)

SUBJECT OF THE INVENTION Process for the preparation of (2,2) paraoylophan and its derivatives of the general formula I, wherein X is hydrogen, halogen, alkyl of 1 to 4 carbon atoms or benzyl and n is 1 to 4, by thermal cleavage of (4-methylbenzyl) -trialkylammonium hydroxide or its A compound of formula II wherein R is C 1 -C 4 alkyl, X and n are as defined above, in a reaction mixture consisting of an inert hydrocarbon solvent and an aqueous alkali hydroxide solution, characterized in that the thermal decomposition takes place in the presence of an alkali sulphite such as sodium or potassium.