SU925953A1

SU925953A1 - Process for producing n-methylbenzoxazolone

Info

Publication number: SU925953A1
Application number: SU802953316A
Authority: SU
Inventors: Олег Константинович Гитин; Владимир Григорьевич Барышников; Иосиф Моисеевич Рутман
Original assignee: Ордена Трудового Красного Знамени Химико-Фармацевтический Завод "Акрихин"
Priority date: 1980-05-30
Filing date: 1980-05-30
Publication date: 1982-05-07

Description

(5) СПОСОБ ПОЛУЧЕНИЯ N-МЕТИЛБЕНЗОКСАЗОЛОНА(5) METHOD FOR PRODUCING N-METHYLBENZOXAZOLONE

II

Изобретение относитс к усовершенствованному способу получени N-метилбензоксазолона, который вл етс полупродуктом в синтезе азафена и азамина, примен емых в медицинской практике в качестве антидепрессантов .The invention relates to an improved process for the preparation of N-methylbenzoxazolone, which is an intermediate in the synthesis of azafen and azamine, used in medical practice as antidepressants.

Известен способ получени N- teтилбензоксазолона путем метилировани бензоксазолона диметилсульфатом с применением избытка едкой щелочи. Выход целевого продукта не указан l).A known method of producing N-tetilbenzoxazolone by methylation of benzoxazolone with dimethyl sulfate using an excess of caustic alkali. The yield of the target product is not specified l).

Недостатком указанного способа вл етс использование большого избытка едкой щелочи.The disadvantage of this method is the use of a large excess of caustic alkali.

Наиболее близким к изобретению по технической сущности и достигаемому эффекту вл етс способ получени N-метилбензоксазолона, который заключаетс в том, что бензоксазолон подвергают взаимодействию с диметилсульфатом в водном растворе едкого натра. Выход В3%. Т.пл. 82-85°С 21.The closest to the invention in its technical essence and the achieved effect is a method for producing N-methylbenzoxazolone, which consists in reacting benzoxazolone with dimethyl sulfate in an aqueous solution of caustic soda. Output B3%. M.p. 82-85 ° C 21.

Недостатками данного способа вл ютс недостаточно высокие выход и качество целевого продукта.The disadvantages of this method are not sufficiently high yield and quality of the target product.

Цель изобретени - повышение выхода и улучшение качества М-метилбензоксазолона ,The purpose of the invention is to increase the yield and improve the quality of M-methylbenzoxazolone,

Поставленна цель достигаетс тем, что согласно способу получени N-метилбензоксазолона, включающему взаимодействие беизоксазолона The goal is achieved by the fact that according to the method of producing N-methylbenzoxazolone, including the interaction of beisoxazolone

10 с едкой щелочью и диметилсульфатом, процесс ведут в среде инертного к диметилсульфату растворител в нейтральной или слабощелочной среде.10 with caustic alkali and dimethyl sulfate, the process is conducted in a solvent inert to dimethyl sulfate in a neutral or weakly alkaline medium.

В качестве растворител исполь15 зуют метанол или смесь метанола и хлористого метилена.Methanol or a mixture of methanol and methylene chloride is used as a solvent.

Claims

The proposed method allows to obtain N-methylbenzoxazolone with a yield of 32% and m.p. 86, To a mixture of benzoxazolone and dimethyl sulfate in methanol or a mixture of methanol and methylene chloride is added a solution of caustic soda in methanol. The reaction mixture is kept under stirring for one hour, if methylene chloride is present in the reaction medium, the latter is chased off, then the reaction mixture is cooled down and the desired product is isolated after adding an aqueous solution of sodium hydroxide to the reaction medium. Example. 3 l of methanol (or 3 l of methylene chloride), 23.0 kg (0.170 kg / m) of benzoxazolone, 25.8 g of dimethyl sulfate are loaded into a reactor with a capacity of 00 l and stirred for 10 min. A solution of 8.15 kg (0.20 kg / m) of caustic soda in 127.0 l of methanol is added to the resulting solution at pH 7-8 by pH (pH meter) for 1020 minutes. At the same time, the temperature of the reaction mixture rises to C. The extract is allowed to stir while stirring and then the reaction mass is cooled to (if methylene chloride is present in the reaction medium, it is first distilled off, then the residue is cooled to). Next, add to the reaction mass 1 l of caustic soda solution to a pH of 8-8.5 and 170 l of water. At the same time, N-methylbenz.oxazolone precipitates. dried at C. 21.8 kg of 99% (21.6 kg of 100%) N-meth are obtained. lbenzoxazolone, tc is 85, t, counting on benzoxazolone, mp 86.5-87 C. After filtration of N-methylbenzoxazolone, the mother liquors are acidified with hydrochloric acid to pH 2, 170 56 56% of heton is distilled off. The residue is cooled to 20 ° C, stirred at this temperature for 2 hours, the precipitate is filtered off, washed with water and dried at 1.89 kg of N-methylbenzoxazolone containing benzoxazolone 2 is obtained. described by calculating the feedstock for the benzoxazolone present in N-methylbenzoxazolone. The total yield of N-methylbenzoxazolone based on benzoxazolone is 92%. Claim 1. Method for producing N-methylbenzoxazolone by reacting benzoxazolone with caustic alkali and dimethyl sulfate, characterized in that, in order to increase the yield and improve the quality of the target product, the process is conducted in a solvent inert to dimethyl sulfate in a neutral or weakly alkaline medium. 2. The method according to claim 1, differs -. y and that the solvent used is methanol or a mixture of methanol and methylene chloride. Sources of information taken into account in the examination To G.de W.Anderson and F.Bell, Migration of Acyl Groups in o-aminophenols. Iii. J. Chem. Soc, c. 2668 ..

2. Gortinska. et al. Method for the preparation of azafen. Chemical Farm Journal, 1973, Vol. 7, No. 6, p. 22 (prototype).