Dimethylformamide → 3-Chloro-1,2-benzisothiazole

Participants

Reaction Steps

A 1 L four-neck flask equipped with a stirrer, a thermometer and a condenser tube was charged with 75.6 g (0.5 mol) of 1,2-benzisothiazol-3-one, 54.8 g (0.75 mol) of N,N-dimethylformamide and 100.0 g of chlorobenzene. While stirring, 71.4 g (0.6 mol) of thionyl chloride was added dropwise thereto over 1 hour at 70° to 80° C., and the mixture was reacted at the same temperature for 8 hours. After terminating the reaction, the liquid reaction mixture was concentrated, and a crude product obtained was distillated under reduced pressure of 0.93 kPa at 128° C. to give 75.1 g (0.45 mol) of 3-chloro-1,2-benzisothiazole. The yield based on the 1,2-benzisothiazol-3-one was 90%.

Provenance & Evidence