Novel sulfonation method for zonisamide intermediate in zonisamide synthesis and their novel crystal forms
AssigneeTeva Pharmaceutical Industries Ltd.
InventorsTamar Nidam, Marioara Mendelovici, Edward Schwartz, Shlomit Wizel
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Abstract
The present invention relates to a novel sulfonation of an intermediate of zonisamide. The sulfonation processes using chlorosulfonic acid as well as acetic anhydride and sulfuric acid in an organic solvent are disclosed. Crystalline forms of benzisoxazole methane sulfonic acid (BOS—H) and its salts (BOS—Na, BOS—Ca, and BOS—Ba) and their novel preparation processes are disclosed.
Claims9
A crystalline BOS—Na Form IV.
A crystalline BOS—Na Form IV, characterized by an X-Ray Powder Diffraction (XRD) having the main peaks at about 4.5, 5.9, 8.8, 11.3, 16.3, 16.9, 19.0, 22.5, 23.9, 24.7, 25.0, 26.8, 28.1, 29.7, 30.9, 32.6, 33.6, 35.5, 36.6±0.2 degrees two theta.
A crystalline BOS—Na Form IV, characterized by a Furier Transform Infra Red Spectroscopy (FTIR) spectrum having the following peaks at about 3431, 1567, 1416, 924, 862 and 586 cm−1.
A process of preparing a BOS—Na Form IV, comprising the steps of:
- 1) preparing a slurry of BOS—Na in the presence of an organic solvent selected from the group consisting of ethanol, isopropanolol and methanol;
- 2) heating the slurry to form a gel;
- and 3) evaporating the organic solvent to obtain the BOS—Na Form IV.
Dependencies are inferred from the claim text.