Process for the preparation of 1,2-benzisothiazoles

Abstract

Abstract 1. A process for the preparation of a 1,2-benzisothiazole of the formula see diagramm : EP0039795,P8,F2 where R**1 is hydrogen, an aliphatic, cycloaliphatic or aromatic radical, a fused phenylene, halogen, alkoxy, nitro or see diagramm : EP0039795,P8,F3 where the individual R**2 's may be identical or different and each denotes hydrogen, an aliphatic, cycloaliphatic, araliphatic or aromatic radical, and R**3 is hydrogen or an aromatic or heterocyclic radical, by reacting an o-haloarylmethyl compound of the formula see diagramm : EP0039795,P8,F1 where X is halogen, R**1 and R**3 have the above meanings, the two R**4 's may be identical or different and are each halogen or together denote an oxo group, with ammonia and elementary sulphur in the presence of an organic solvent at elevated temperature, wherein the reaction is carried out with 18 to 31% strength by weight aqueous ammonia solution at a pressure of from 0.8 to 1.2 bar and a temperature of from 65 to 110 degrees C in the presence of a disubstituted sulphoxide, sulphone or formamide, or a mixture thereof, as solvent.

Inventors

• 👤 Helmut Dr. Hagen
• 👤 Juergen Dr. Markert
• 👤 Hans Dr. Ziegler

Bibliographic Details