1.2- Benzisothiazole 4- chloro-7-nitro

The introduction of substituents into the position 3 does not change the reaction course [165, 167-169], 4-Amino-7-nitrobenzisothiazole in the sulfuric-nitric mixture forms 5,7-dinitro derivative in low yield [170], 4-Chloro-7-nitro-l,2-benzisothiazole was obtained as a result of the nitration of 4-chloro-l,2-benzisothiazole [171,172], 5-Hydroxy-l,2-benzothiazole is nitrated to the position 4, and in case of 5-hydroxy-4,6-dibromo-l,2-benzisothiazole a substitutive nitration to form 5-hydroxy-6-bromo-4-nitro isomer occurs [173],... 

The 7-aminobenzisothiazole 148, prepared by reduction of the 4-chloro-7-nitro-benzisothiazole, was diazotized in concentrated hydrochloric acid and the 4-chloro benzisothiazole-7-diazonium chloride 149 was obtained (71JCS(C)3994, Scheme 50). 

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