Acetic Acid → Benzothiazole, 6-chloro-2-methyl-

Participants

Reaction Steps

112.25 parts of the sodium salt of 4-chloro-2-mercaptophenylurea, which salt is obtainable according to Example 6 of European Pat. No. 0,039,483, are suspended in 450 parts of glacial acetic acid in an autoclave. The pressure vessel is closed and heated slowly to 150° C.-160° C. in the course of 2 hours, a pressure of about 5 bar being established. The water formed is discharged continuously via a pressure release valve. The reaction is complete after 5 hours. The autoclave is cooled to room temperature and opened, the reaction mixture is allowed to run into 1000 parts of water, and the precipitated 6-chloro-2-methylbenzothiazole is isolated by filtration, washed neutral and dried in vacuo at 40° C. 85.6 parts of a product of the formula ##STR21## of melting point 85° C.-86° C. are obtained; this corresponds to a yield of 93.3% of theory, based on sodium salt employed.

Provenance & Evidence