ClCl.BrBr.N([O-])=O.[Na+].ClC1SC2C=C(Cl)C=CC=2N=1.Cl[C:21]1[CH:30]=[CH:29][C:24]2[N:25]=[C:26]([NH2:28])[S:27][C:23]=2[CH:22]=1.ClC1SC2C=C([F:41])C=CC=2N=1>>[F:41][C:21]1[CH:30]=[CH:29][C:24]2[N:25]=[C:26]([NH2:28])[S:27][C:23]=2[CH:22]=1The 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.
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