| abstract |
[PROBLEMS] (1R, 5R, 6S) -p-nitrobenzyl-2- (diphenylphosphoryloxy) -6-[(R) -1-hydroxyethyl] -1-methyl-carbapenem-3-carboxylate (MAP) Of the preparation of type II crystals. (1R, 5R, 6S) -p-nitrobenzyl-2- (diphenylphosphoryloxy) -6-[(R) -1-hydroxyethyl] -1-methyl-carbapenem-3- Carboxylate (MAP) is dissolved in dichloromethane, chloroform or acetone, and then diethyl ether, isopropyl ether, normal hexane, normal heptane or cyclohexane is dropped into this solution to crystallize. [Effect] It is possible to obtain a high-purity and high-yield MAP type II crystal which can be mass-produced by a simple method without performing a separate cooling process to obtain a crystal form. [Selection] Figure 2 |