反应详情

The starting compounds of the formula III wherein X is chlorine or bromine can be prepared from corresponding 2-benzothiazole-amines by reaction with a warm concentrated hydrohalic acid and sodium nitrite [See H. Mazzone and G. Pappalardo, Il Farmaco, Ed. Sc. 32, 348-354 (1977)]. Thus, for example, 2,6-dichlorobenzothiazole (m.p. 99°-101° C.) can be obtained from 6-chloro-2-benzothiazole-amine, and 2-chloro-6-fluorobenzothiazole (m.p. 92°-93° C.) can be obtained from 6-fluoro-2-benzothiazole-amine.