CRYSTALLINE FORMS OF CARBAPENEM ANTIBIOTICS AND METHODS OF PREPARATION

摘要

A process for preparing a crystalline, carbapenem monosodium salt of formula IIa, characterized by the steps a) adding about 10 to 30 % of an organic solvent to an aqueous solution of the carbapenem, b) cooling the resulting solution to less than -5 DEG C, c) adjusting the pH using a solution containing an acid in an organic solvent to give the appropriate pH for crystallization, and d) crystallizing the compound by adding methanol, and a C2-5 alcohol at between -5 and -25 DEG C.