Production method of 1,2- benzisothiazole-3-ketone

Abstract

A preparation method of 1, 2-benzisothiazole-3-ketone (BIT) is a BIT synthetic route realized by adopting a 2-chlorobenzonitrile method which selects water to replace chlorobenzene as a sulfurization and chlorination solvent. By adopting the method, the pollution of the chlorobenzene to atmosphere and water body is thoroughly eliminated and the total production cost of BIT is greatly reduced. The method comprises the following steps: chlorobenzonitrile is added with water accounting for 0-50% of the mass of the chlorobenzonitrile, and is added with a catalyst, then is added with sodium methyl mercaptide solution dropwise for a sulfuration reaction after heating, and the reactant is cooled for standing, a lower layer water phase is given out, water is added to rinse an upper layer organic phase, then the organic phase obtained in the sulfurization process is added with water accounting for 30%-200% of the volume of the organic phase; and chlorine is introduced into for reacting for 2-5h while stirring, then filtration is carried out to obtain a filter cake after the organic phase completely disappears and a white-pink suspended solid is produced, the filter cake is washed by clear water and is dried at low temperature to obtain the BIT product.

Description

technical field

[0001] This method proposes a kind of production method of 1,2-benzisothiazol-3-ketone (BIT), specifically, a kind of o-chlorobenzonitrile method production that replaces chlorobenzene with water as the solvent of vulcanization and chlorination BIT method. Background technique

[0002] 1,2-Benzisothiazol-3-one is mainly used as biological fungicide. At present, in the industrial route of using o-chlorobenzonitrile as raw material, sulfidation and chlorination of sodium methyl mercaptide to synthesize BIT, chlorobenzene needs to be used as a solvent, and the consumption of chlorobenzene per ton of product is 1-1.4 tons, which not only increases the production cost but also consumes Chlorobenzene enters the atmosphere and waste water causing air pollution and water pollution. Contents of the invention

[0003] The present invention proposes a BIT synthesis route using water instead of chlorobenzene as a solvent for vulcanization and chlorination through the...