CS248342B1 - Process for the production of dichloro- (2,2-paracyclophane) - Google Patents

Abstract

The method for producing dichloro-/2,2/paracyclophane from a quaternary ammonium salt of the general formula III, where R is the same or different alkyl with 1 to 12 carbon atoms and X is a chlorine, bromine or iodine atom, proceeds in such a way that this quaternary ammonium salt is treated with a strong base in a reaction medium formed by a mixture of an inert hydrocarbon solvent and dimethyl sulfoxide, and the resulting ammonium base is then decomposed in this medium without isolation at an elevated temperature of 40 to 140 °C, preferably 60 to 95 °C. The strong base may be sodium hydroxide, potassium hydroxide or sodium dimethyl sulfoxide. The hydrocarbon solvent may be aromatic hydrocarbons, benzene, toluene or xylene.

Description

The present invention relates to a process for the preparation of dichloro- (2,2) paracyclophan. Dichloro- (2,2) paracyclophan is a known compound of formula (I) for the preparation of a polydichloro-p-xylylene polymer.

Processes for the preparation of dichloro- (2,2) paracyclophane based on chlorination (2,2) paracyclophane / US are known. U.S. Pat. No. 3221008, 3288728, 3342739 /.

A disadvantage of the above-mentioned processes for the preparation of dichloro-2 (paracyclophane) is that they require, as a starting compound (2,2), paracyclophane, a compound which is difficult to obtain and expensive. Another disadvantage of the described processes for the preparation of dichloro / 2,

2) Paracyclophan is the fact that the reaction product resulting from chlorination (2,2) of paracyclophan contains, in addition to the dichloro (2,2) paracyclophan, unreacted starting material, a dichloro derivative with chlorine atoms attached to one aromatic ring and chloro derivatives with more than two chlorine atoms in molecule. Due to further use, the production of a precisely defined polymer, said additives are undesirable and must be removed, for example, by rectification under reduced pressure.

Said drawbacks of the preparation of dichloro- (2,2) paracyclophan are solved by the process of the invention, wherein the quaternary ammonium base of formula II, wherein R is the same or different alkyl having 1 to 12 carbons, decomposes at a temperature of 40 to 140 ° C, preferably 60 to 95 ° C in a reaction system consisting of an inert hydrocarbon solvent and dimethylsulfoxide and a strong base solution. The aromatic hydrocarbons benzene, toluene and xylene may, for example, be an inert hydrocarbon solvent according to the invention. The alkyl radical R according to the invention is preferably methyl or ethyl.

248 342

The starting quaternary ammonium base IX is prepared according to the invention preferably directly in a reaction system consisting of an inert hydrocarbon solvent and dimethyl sulfoxide by treating a corresponding quaternary ammonium salt III with a strong base, wherein R is the same or different alkyl having 1 to 12 carbons and X is chlorine. a bromine atom or an iodine atom.

Further, the quaternary ammonium base II can be prepared in a manner known per se from the corresponding halogenated derivative IV, wherein X is as defined above by reaction with trimethylamine to form the quaternary ammonium salt III, which is converted to the ammonium base II as described above.

An advantage of the process according to the invention is that the quaternary ammonium base is not isolated, that the purification of the intermediates is eliminated and that the yields are between 80 and 85%. An essential advantage of the process according to the invention is that the resulting dichloro- (2,2) paracyclophane has a precisely defined structure, characterized by the presence of only one chlorine atom on each benzene nucleus and hence the polymer prepared from this substituted paracyclophane has a precisely defined structure and properties. so far, no known procedure has been allowed.

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

Example 1

To a solution of 120 g of sodium hydroxide in 100 ml of water was added 4 L of toluene and 750 ml of dimethylsulfoxide. Under stirring for 1 hour, a solution of 265 g of III in 100 ml of water was added at 50 ° C. The resulting mixture was stirred at 60 ° C for 8 hours and at 90 ° C for a further 8 hours. After cooling, the phases were separated, the organic was washed with water, filtered and evaporated to dryness. 112.0 g of dichloro- (2,2) paracyclophan were obtained. Yield 85.0%.

Example 2

219.5 g of IV (x-Br) were dissolved in 4 L of toluene. With stirring at 2 ° C, 66 g is added to the solution over 1.5 hours

AND

- 3 248 342 trimethylamine. After completion, the mixture was stirred at 20 ° C for 8 hours. 200 ml of water and 750 ml of dimethyl sulfoxide are added to the mixture with stirring. After heating to 50 ° C, a solution of 120 g of NaOH in 100 ml of water was added over 1 hour. The resulting mixture was stirred at 80 ° C for 8 hours and at 90 ° C for a further 8 hours. After cooling, the phases are separated, the organic phase is washed with water, filtered and evaporated to dryness. Yield 110.8 g of dichloro- (2,2) paracyclophan, i.e. 80 wt.

Claims (6)

A process for the preparation of dichloro- (2,2) paracyclophane from a quaternary ammonium salt of the general formula III, wherein R is the same or different alkyl of 1 to 12 carbon atoms and X is a chlorine, bromine or iodine atom, characterized in that the quaternary ammonium salt acts as a strong base in a reaction medium consisting of a mixture of an inert hydrocarbon solvent and dimethylsulfoxide and the resulting ammonium base decomposes at elevated temperatures of 40 to 140 ° C, preferably 60 to 95 ° C without isolation 2. The method of item 1 _; characterized in that the strong base is sodium hydroxide. 5. The process of claim 1 wherein the strong base is potassium hydroxide. 4. The process of claim 1 wherein the strong base is sodium dimethylsulfoxide. 5 « 2. The method of claim 1 wherein the body is an aromatic hydrocarbon. 2. The method of claim 1 wherein the solvent is benzene. 7. The process of claim 1 wherein the solvent is toluene. 8. The method of item 1, wherein the solvent is xylene. The process of claim 1 wherein the hydrocarbon solvent is a hydrocarbon oil AND 248 342 Cl CH ₂ N (R) ₃ OH HH ₃ C-OY ₂ W (R) ₃ X 32 H ₃ C 4