- PURE 1,2-BENZISOXAZOLE-3-METHANE-SULFONIC ACID SODIUM SALT AND PURIFICATION PROCESS
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The present invention provides chemically pure sodium salt of 1,2-benzisoxazofe-3-methane-sulfonic acid, the sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay, or chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay, and processes for preparing the same via purification. The present invention also provides monohydrate form of the chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid, the sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay, or chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay. Furthermore, the present invention provides anhydrous form of the chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid, the sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay, or chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay. One of the embodiments of the present invention is directed to a process for preparing zonisamide using the chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid, the sodium salt of 1,2-benzisoxazole-3- methane-sulfonic acid of high assay, or chemically pure sodium salt of 1,2-benzisoxazole-3-methane-sulfonic acid of high assay.
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Page/Page column 14
(2008/06/13)
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- Method for preparing benzisoxazole methane sulfonyl chloride and its amidation to form zonisamide
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The present invention relates to a process of preparing benzisoxazole methane sulfonic acid-chloride (BOS-Cl) as an zonisamide intermediate via chlorination of benzisoxazole methane sulfonate. The present invention also disloses a process of preparing zonisamide via amidation of BOS-Cl. 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.
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