MANUFACTURING METHOD OF 6-O-METHYLERYTHROMYCIN A FORM II FROM 6-O-METHYLERYTHROMYCIN A

摘要

PURPOSE: A manufacturing method of 6-O-methylerythromycin A form II using mixed solvent is provided which enables to obtain highly pure 6-O-methylerythromycin A form II in high yields. The precipitation of by-products can be minimized by controlling the mixing ratio of the solvents CONSTITUTION: 6-O-methylerythromycin A form II can be obtained by recrystallizing6-O-methylerythromycin A(formula 1). A recrystallizing method comprises the following steps. They are as follows: a) 6-O-methylerythromycin A is solubilized completely by using tetrahydrofuran which is cyclic ether compound having high solubility, at room temperature or low temperature(about 0°C); b) the solution is filtered if necessary, and then the mixed solvent of C5-C12 hydrocarbon and C4-C10 ether having low solubility is added into the (filtered) solution to form pure crystal; c) the produced pure crystal, 6-O-methylerythromycin A form II, is vacuum dried at about 45-50°C. The mixing ratio of tetrahydrofuran to the second solvent is 1: 1-5 and the precipitation of by-products can be minimized by controlling the mixing rate of the solvents.