Patent ID: 7081539
Filing Date: 2006-07-25
Classification: C07D

Abstract:
1. A process for the preparation of 1,2-benzisoxazole-3-methanesulfonamide, which comprises: (a) reacting 4-hydroxycoumarin, hydroxylamine or an acid addition salt thereof, and a base in water to give a first mixture; (b) acidifying the first mixture, adding 1,2-dichloroethane thereto to give a second mixture, and removing an aqueous layer from the second mixture to give a third mixture containing 1,2-benzisoxazole-3-acetic acid and 1,2-dichloroethane; (c) removing water from the third mixture by distillation to give a fourth mixture, adding chlorosulfonic acid to the fourth mixture and reacting the mixture to give a fifth mixture, and adding a base to the fifth mixture to give a sixth mixture containing an alkali metal salt of 1,2-benzisoxazole-3-methanesulfonic acid; (d) adding phosphoryl chloride to the sixth mixture, and reacting the mixture to give a seventh mixture containing 1,2-benzisoxazole-3-methanesulfonyl chloride; (e) adding ammonia to the seventh mixture and reacting the mixture to give an eighth mixture containing 1,2-benzisoxazole-3-methanesulfonamide; and (f) isolating the 1,2-benzisoxazole-3-methanesulfonamide.