| 摘要 |
PROBLEM TO BE SOLVED: To provide benzoate of 4"-deoxy-4"-epi-methylaminoavermectin B1a/B1b in thermodynamically stable crystal form of half-hydrated product (type B), and a production method thereof. SOLUTION: This production method is provided in which a compound in crystal form A, C or D is dissolved in an organic solvent at about 50 to 60°C and treated with a necessary amount of water, and the resulting mixture is seeded with a crystal of type B, cooled to a temperature of about 15 to 30°C, and aged at the temperature for about 2 to 4 hours, and further cooled to a temperature of about 5°C over about 1 to 2 hours, and the resulting crystalline substance is filtered, collected and dried under vacuum. COPYRIGHT: (C)2007,JPO&INPIT
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