| 摘要 |
PURPOSE: Provided is a process for the preparation of 6-O-methylerythromycin A Form II comprising converting erythromycin A to 6-O-methylerythromycin A and treating the 6-O-methylerythromycin A with a number of common organic solvents or mixtures of common organic solvents. CONSTITUTION: Provided is a process for preparing 6-0methylerythromycin A Form II comprising (a) converting erythromycin A to 6-O-methylerythromycin A; (b) treating the 6-O-methylerythromycin A prepared in step (a) with a solvent selected from the group consisting of (i) an alkanol of from 1 to 5 carbon atoms, provided said alkanol is not ethanol or isopropanol, (ii) a hydrocarbon of from 5 to 12 carbon atoms, (iii) a ketone of from 3 to 12 carbon atoms, (iv) a carboxyl ester of from 3 to 12 carbon atoms, provided said carboxyl ester is not isopropyl acetate, (v) an ether of from 4 to 10 carbon atoms, (vi) benzene, (vii) benzene substituted with one or more substituents selected from the group consisting of alkyl of from one to four carbon atoms, alkoxy of from one to four carbon atoms, nitro, and halogen, (viii) a polar aprotic solvent, (ix) a compound having the formula HNR1R2 wherein R1 and R2 are independently selected from hydrogen and alkyl of one to four carbon atoms, provided that R1 and R2 are not both hydrogen, (x) water and a second solvent selected from the group consisting of a water miscible organic solvent and a water miscible alkanol, (xi) methanol and a second solvent selected from the group consisting of a hydrocarbon of from 5 to 12 carbon atoms, an alkanol of from 2 to 5 carbon atoms, a ketone of from 3 to 12 carbon atoms, a carboxyl ester of from 3 to 12 carbon atoms, an ether of from 4 to 10 carbon atoms, benzene, and benzene substituted with one or more substituents selected from the group consisting of alkyl of from one to four carbon atoms, alkoxy of from one to four carbon atoms, nitro, and halogen, and (xii) a hydrocarbon of from 5 to 12 carbon atoms and a second solvent selected from the group consisting of a ketone of from 3 to 12 carbon atoms, a carboxyl ester of from 3 to 12 carbon atoms, an ether of from 4 to 10 carbon atoms, benzene, benzene substituted with one or more substituents selected from the group consisting of alkyl of from one to four carbon atoms, alkoxy of from one to four carbon atoms, nitro, and halogen, and a polar aprotic; and (c) isolating the 6-O-methylerythromycin A Form n crystals. |
