METHOD FOR PREPARING BENZISOXAZOLE METHANE SULFONYL CHLORIDE AND ITS AMIDATION TO FORM ZONISAMIDE

摘要

The present invention relates to a process of preparing benzisoxazole methane sulfonic acid-chloride (BOS-CI) as an zonisamide intermediate via chlorination of benzisoxazole methane sulfonate. The present invention also disloses a process of preparing zonisamide via amidation of BOS-CI. More particularly, the present invention provides a process of preparing zonisamide, comprising the steps of : a) chlorinating BOS; salts or esters thereof, with SOCl2 in an organic solvent and/or in the presence of a catalyst to form BOS-Cl; and b) amidating BOS-Cl in the presence of ammonia selected from the group consisting of aqueous ammonia in a biphasic system, masked ammonia and dry ammonia to form zonisamide.