Benzisothiazole → 3-Chloro-1,2-benzisothiazole

Participants

Reaction Steps

In a 300 ml four-necked flask equipped with a stirrer, a thermometer, and a condenser, 100 g of monochlorobenzene was placed in advance, to which 33.4 g (0.2 mol) of 2-(methylthio)benzaldehyde oxime was added under nitrogen atmosphere. 25.2 g (0.21 mol) Of thionyl chloride was added dropwise thereto while stirring at a temperature of from -10° to -15° C. and allowed to react for 1 hour at the same temperature. After the termination of the reaction, 15.6 g (0.22 mol) of chlorine was continuously blown into the reaction mixture containing 1,2-benzisothiazole while stirring at a temperature of from 70° to 80° C. and allowed to react for 1 hour at the same temperature. After the termination of the reaction, the reaction mixture was subjected to distilling off of the solvent and then to distillation under reduced pressure to give 32.6 g of 3-chloro-1,2-benzisothiazole. The yield was 96% to the 2-(methylthio)benzaldehyde oxime.

Provenance & Evidence