- Green and environment-friendly zonisamide synthesis method
-
The invention discloses a green and environment-friendly zonisamide synthesis method which includes the steps: adding 1, 2-sulfamethoxazole-3-sodium methanesulfonate or 1, 2-sulfamethoxazole-3-ammonium methanesulfonate into methylbenzene, heating, reflowing and reducing temperature to 10-35 degrees, adding triphosgene and catalysts, heating, stirring and reacting mixture; pumping in a vacuum manner to remove redundant unreacted triphosgene, leading anhydrous ammonia until pH (potential of hydrogen) to be 9-10; centrifuging out solids, leaching the solids by the aid of methylbenzene, adding water to stir mixture, centrifuging and drying the solids, and performing recrystallization for the dried solids by the aid of methyl alcohol to obtain zonisamide crystal. The zonisamide synthesis method is safe, reliable, green, environmentally friendly, high in yield, low in cost, simple in post-processing and suitable for mass industrial production, and raw materials are easily obtained.
- -
-
Paragraph 0047; 0048
(2017/08/29)
-
- 1,2-BENZISOXAZOLE-3-METHANE-SULFONIC ACID AMMONIUM SALT
-
The present invention provides substantially isolated ammonium salt of 1,2- benzisoxazole-3-methane sulfonic acid (BOS-NH4), which can be crystalline. The present invention also provides substantially chemically pure BOS-NH4, which is non- hygroscopic or slightly hygroscopic. Another aspect of the present invention is directed to processes of preparing the BOS-NH4. The present invention also provides processes for preparing l,2-benzisoxazole-3-methane-sulfonyl chloride (BOS-Cl) using the BOS-NH4. The present invention also provides processes for preparing zonisamide using the BOS-NH4 or BOS-Cl.
- -
-
Page/Page column 15-16
(2008/06/13)
-
- Process for the preparation of zonisamide and the intermediates thereof
-
The present invention provides a novel and improved process for the preparation of Zonisamide and the intermediates thereof. In one aspect of the present invention, the process provides for: the preparation and isolation of a novel crystalline form of anhydrous 1,2-benzisoxazole-3-methanesulfonic acid of formula 1; the direct chlorination of the acid of formula 1 into its acid chloride of formula 2; and the in situ conversion of the intermediate acid chloride of formula 2 into Zonisamide.
- -
-
Page/Page column 7
(2008/06/13)
-
- PURE 1,2-BENZISOXAZOLE-3-METHANE-SULFONIC ACID SODIUM SALT AND PURIFICATION PROCESS
-
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.
- -
-
Page/Page column 13
(2008/06/13)
-
- Process for the preparation of zonisamide
-
The present invention provides an improved process for the preparation of zonisamide or a derivative thereof comprising (a) reacting 1,2-benzisoxazole-3-methane-sulfonic acid with a halogenating agent in a first organic solvent to provide benzisoxazole methane sulfonyl halide; and, (b) reacting benzisoxazole methane sulfonyl halide with an amine in a second organic solvent to form zonisamide or a derivative thereof.
- -
-
Page/Page column 3; 4
(2008/06/13)
-
- A PROCESS FOR THE MANUFACTURE OF ZONISAMIDE
-
The present invention describes an improved process for the preparation of 1,2Benzisoxazole-3-methanesulphonamide (Zonisamide), a well known anti-epileptic agent which possesses anti-convulsant and anti-neurotoxic effects. Other aspect of this invention are isolation of a key intermediate, viz., crystalline sodium chloride associated 1,2Benzisoxazole-3-methane sodium sulfonate (BOS-Na:NaCl). The isolated crude BOSNa:NaCl is directly converted to Zonisamide using controlled molar ratio of chlorosulfonic acid to avoid the disulfonated side products. The analytical characteristics like IR and XRD data of the BOS-Na:NaCl are also reported to confirm its nature.
- -
-
Page/Page column 10
(2010/02/11)
-
- Method for preparing benzisoxazole methane sulfonyl chloride and its amidation to form zonisamide
-
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.
- -
-
-
