IMPROVED METHOD FOR PRODUCING 8-NITRO-2-(1H-TETRAZOL-5-YL)-4H-1-BENZOPYRAN-4-ONE FROM 8-NITRO-2-CYANO-4H-1-BENZOPYRAN-4-ONE AND CONVERTING RESULTANT PRODUCT INTO HYDROCHLORIDE SALT OF 8-AMINO-2-(1H-TETRAZOL-5-YL)-4H-1-BENZOPYRAN-4-ONE

摘要

PROBLEM TO BE SOLVED: To provide an improved method for the conversion of 8-nitro-2-cyano-4H-1-benzopyran-4-one into 8-nitro-2-(1H-tetrazol-5-yl)-4H-1-benzopyran-4-one which uses sodium azide together with a zinc halide in water.;SOLUTION: The compound, 8-nitro-2-(1H-tetrazol-5-yl)-4H-1-benzopyran-4-one is further converted into a hydrochloride salt of 8-amino-2-(1H-tetrazol-5-yl)-4H-1-benzopyran-4-one by using stannous chloride in a hydrochloric acid solution.;COPYRIGHT: (C)2008,JPO&INPIT