Piperazine → 3-(1-Piperazinyl)-1,2-benzisothiazole

Participants

Reaction Conditions

Reaction Steps

304.2 g (3.53 mol) of piperazine, 7.5 g of chlorobenzene, 39.8 g (0.235 mol) of 3-chloro-1,2-benzisothiazole were placed in a four-neck 1000 ml flask equipped with a stirrer, a thermometer, a dropping funnel and a condenser, which was heated to stir at about 120° C. for 20 hours. After excess piperazine was removed with water, the reaction mixture was made acidic with hydrochloric acid, extracted into an aqueous layer, which was made alkaline with aqueous sodium hydroxide to obtain 24.4 g (m.p. 89 to 90° C.) of 3-(1-piperazinyl)-1,2-benzisothiazole as crystals. Yield from 3-chloro-1,2-benzisothiazole was 47.4%.

Provenance & Evidence