反应详情

To a solution of 4.6 g of 2-aminothiophenol in 50 ml of dimethylformamide was added dropwise 9.55 g of methyl 2,4-dibromobutyrate with stirring at room temperature. After stirring one hour, the reaction mixture was poured into water to give crystals of 2-(2-bromoethyl)-2H-1,4-benzothiazin-3(4H)-one. The crystals were collected by filtration and washed with water, n-hexane and cold methanol. The yield was 6.32 g (63.3%). Recrystallization from ethyl acetate gave prisms, m.p. 151°-152° C.

1. stirringAfter stirring one hour