Novel synthesis method of N-substituted benzisothiazoline-3-ketone derivative

Abstract

The invention discloses a novel synthesis method of an N-substituted benzisothiazoline-3-ketone derivative. The preparation method comprises the following steps: by taking a dithiosalicylic acid derivative and sulfur as raw materials, introducing chlorine or bromine to obtain a halogenated thiobenzoyl halide derivative, then preferably dropwise adding a mixed solution of primary amine and tertiaryamine, and carrying out reaction and ring closing to obtain the N-substituted benzisothiazole-3-ketone. The method disclosed by the invention is simple in process, safe and controllable, and easy forindustrial large-scale production.

Description

technical field [0001] The invention relates to a synthesis method, in particular to a new synthesis method of N-substituted benzisothiazolin-3-one derivatives. Background technique [0002] Isothiazolinone compounds are a class of high-efficiency broad-spectrum fungicides. The most famous product representatives are Casson, DCOIT, OIT, etc., which are widely used in cosmetics, papermaking, metal cutting fluids, paints, coatings, and plastic products. Anti-corrosion and sterilization. With the long-term use of isothiazolinone compounds, some bacteria have developed drug resistance. So phenyl-containing N-substituted benzisothiazolin-3-ones have been widely used, famous products such as BIT, BBIT, MBIT and so on. [0003] Its synthesis method has long been concerned by large companies at home and abroad, and many synthesis methods have been reported so far. However, due to various reasons, many synthetic methods have more or less defects, resulting in low product quality o...

AI Technical Summary

Problems solved by technology

The difficulty of method one is that the residue of moisture has a great influence on the reaction, the removal of water from sodium sulfide is very important, and the reaction temperature is very high, and it is difficult to realize industrialization when NMP with a high boiling point is used at the same time; method two is that the raw materials in each step are It is solid, and these raw materials are difficult to dissolve in conventional solvents, and the reaction process is more complicated; method three has too many by-products; method four and five are the methods commonly used in industrialization at present, but need to use malodorous sodium alkyl mercaptan salt , and release low-boiling-point halogenated hydrocarbons in the reaction, which is unfavorable for environmental protection; the difficulty of method six is ​​the synthesis of raw material sulfur chloride compounds. At present, raw materials such as thionyl chloride and sulfuryl chloride are generally used. The raw materials are sensitive to air humidity, and the environment of the place of use is relatively high. At the same time, a large amount of sulfur dioxide is released, and the pressure on environmental protection is relatively high.

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