The nitration of sym-triazolo[3,4-b]benzothiazole
The nitration of sym-triazolo[3,4-b]benzothiazole (I) with a mixture of nitric and sulfuric acids has given 6-nitro-sym-triazolo[3,4-b]benzothiazole (II). The structure of II was established by comparing its properties (mp, PMR spectrum) with those of the 7-nitro-sym-triazolo[3,4-b]-benzothiazole (III) obtained by the ring closure of 2-hydrazino-6-nitrobenzothiazole (VI) with orthoformic ester. Compounds II and III have been converted into the corresponding acetylamino derivatives. Saponification of the acetyl groups has given amino derivatives of I.