Abstract

Bhikan J. Khairnar, Pravin S. Girase and B. R. Chaudhari^*

A series of novel 3-methyl-7-substituted-4H-1, 4-benzothiazine-2-carbohydrazide & corresponding thiosemicarbazide have been synthesized. The 1, 4- benzothiazine thiosemicarbazides i.e. 2-[(3-methyl-7-substituted-4H-1, 4-benzothiazin-2-yl) carbonyl]-N-aryl-hydrazine carbothiamide when cyclised with 2N sodium hydroxide via intramolecular dehydrative cyclisation gave benzothiazonyl triazoles. The given procedure is in 4-steps. The final step is an intramolecular cyclisation is achieved by ultrasound irradiation & also by conventional method. In general, substantial improvement in rates and increase in modest yields observed when reactions are carried out under sonication, compared with classical heating method. The structures of these compounds have been elucidated by spectral (IR, 1H NMR) analysis.

1,4-Benzothiazine;1,2, 4-triazole; thiosemicarbazide; ultrasonic irradiation

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