| 摘要 |
<p>A process for preparing various polymorphic modifications of 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid each selectively by crystallization under the specific conditions determined by temperature and methanol/water ratio of the mixed solvent to be used; and polymorphic modifications of 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid as obtained by this process. A process of subjecting a specific polymorphic modification of the above acid to heating and vacuum drying to thereby obtain another polymorphic modification of the acid or an amorphous modification thereof; and polymorphic or amorphous modifications of the acid as obtained by this process.</p> |
