CS257195B1 - Process for the preparation of chlorinated 2-chloromethanesulfonylaminodiphenylethers - Google Patents

Abstract

The purpose of the solution is a method for preparing chlorinated 2-chloromethanesulfonylaminodiphenyl ethers by reacting chloromethanesulfonyl chloride with the corresponding substituted 2-aminodiphenyl ether in an organic solvent in the presence of pyridine as a catalyst, such that the aqueous solution containing pyridine hydrochloride that is discarded for chloromethanesulfonylation is converted to the free base, which is extracted with an organic non-polar solvent, the resulting extract is distilled and the anhydrous fraction containing pyridine with the solvent is used for further chloromethanesulfonylation.

Description

. The present invention relates to a process for the preparation of 2-chloromethanesulfonylaminodiphenyl ethers of chloromethanesulfo-. by the reaction of the corresponding 2-aminodiphenyl ethers with the recycling of pyridine as a catalyst.

These compounds of the general formula

X-

X

NHSO ₂ CH ₂ Cl

X wherein X is either Cl or H, wherein at least one X represents Cl at the 4 or 4 'position are used after subsequent chlorination to protect wool and polyamide textile materials from pests.

The prior art process consisted of chloromethanesulfonylation of the corresponding aminodiphenyl ethers using pure pyridine as catalyst, after which the pyridine was separated by washing the reaction mixture in the form of an acidic aqueous solution containing still hydrolytically formed chloromethanesulfonic acid and other impurities. This solution containing pyridine hydrochloride was isolated by salting out with a considerable excess of sodium hydroxide as a newly formed phase, which after separation was freed from other impurities by distillation, then dewatered with solid sodium hydroxide and finally de-watered. The obtained pure pyridine was returned to production.

The disadvantages of this process are the considerable consumption of sodium hydroxide due to the dual salting-out of pyridine, which, in addition to the cost increase, entails an increase in wastewater production. Secondly, the process is machinery-intensive, including energy consumption.

The above-mentioned disadvantages are eliminated by the process according to the invention, characterized in that the aqueous pyridine hydrochloride-containing aqueous solution which remains after chloromethanesulfonylation is converted to the free base, extracted with an organic non-polar solvent, distilled off. . *

The pyridine extraction can be carried out both continuously and desontinuously.

He did

500 g of pyridine wastewater containing 106.9 g of pyridine are made alkaline

162 g of a 40% free NaOH solution.

To the treated solution is added

500 g of toluene and mix both phases thoroughly.

After separation of the non-polar phase, the aqueous phase is subjected to a second extraction of 500 g of toluene. The second toluene extract is used for the first extraction of the alkalized pyridine waste water.

The first extract is distilled to give a virtually anhydrous two-component solution after separation of the front water containing fraction:

18.4% pyridine and 71.6% toluene. The front water containing fractions is returned to the second toluene fraction. The two - component solution obtained is used as follows:.

To 409.5 g of a toluene solution containing

127 g of 4,4'-dichloro-2-aminodiphenylether are added 213.3 g of a two-component solution of pyridine and g of chloromethanesulphochloride. After proper mixing, the contents were allowed to react for 24 hours.

Water (50 ml) was added to the reaction mass and stirred at 60 ° C for 1/2 hour. After phase separation, the toluene layer was separated and poured into 2,500 ml of water and the aqueous phase containing pyridine hydrochloride was used again for regeneration, basified with NaOH to a mimosity positive reaction while stirring the two phases. After separation of the aqueous phase, it is acidified to pH 3 with hydrochloric acid. The precipitated amide is filtered off, washed with water and dried to give 4,4'-dichloro-2-chloromethanesulfonylamino-diphenyl ether in 76% yield for the amine used.

Example 2

The procedure is the same as in Example 1 except that 420 g of a toluene solution containing

144 g of 2 ', 4,4'-trichloro-2-aminodiphenyl ether. After chloromethylation using regenerated pyridine, 2 ', 4,4'-trichloro-2-chloromethanesulfonylaminodiphenyl ether is obtained in 78% yield per amine used.

Example 3

The procedure is again the same as in Example 1, except that 400 g of a toluene solution containing

110 g of 4-chloro-2-aminodiphenyl ether. After chloromethylation using regenerated pyridine, 4-chloro-2-chloromethanesulfonylaminodiphenyl ether is obtained in a yield of 75% of theory for the amine used.

Claims (1)

A process for the preparation of chlorinated 2-chloromethanesulfonylaminodiphenyl ethers of general formula Mowo. x nhso ₂ ch ₂ ci wherein X is Cl or H wherein at least one X represents Cl in the 4 or 4 'position by reaction of chloromethanesulfonyl chloride with the corresponding substituted 2-aminodiphenyl ether in an organic solvent under the catalytic action of pyridine; The pyridine hydrochloride is converted to the free base, which is extracted with a solvent, and the resulting extract is distilled, and the anhydrous pyridine-containing fraction with the solvent is used for further chloromethanesulfonylation.