| 摘要 |
PROBLEM TO BE SOLVED: To provide a crystalline form of 4-[3,5-bis(2-hydroxyphenyl)-[1,2,4]triazol-1-yl]benzoic acid, its amorphous form, a production method of the same, and a composition comprising them.SOLUTION: A production method of crystalline form B of 4-[3,5-bis(2-hydroxyphenyl)-[1,2,4]triazol-1-yl]benzoic acid comprises the following steps: (a) heating crystalline form A of 4-[3,5-bis(2-hydroxyphenyl)-[1,2,4]triazol-1-yl]benzoic acid to its melting point of about 261°C or higher, (b) cooling the melted product of the step (a) to about room temperature or below to obtain amorphous form, (c) heating the amorphous form of the step (b) to a temperature of 95°C or higher, preferably 190°C or higher to recrystallize to the crystalline form B, and (d) by cooling to the room temperature, isolating crystalline form B of 4-[3,5-bis(2-hydroxyphenyl)-[1,2,4]triazol-1-yl]. |
