| 摘要 |
A process for the preparation of fumaric acid salts of compounds of general formula (II) (wherein R1 is lower alkyl; and R2 is lower alkyl), characterized by reacting a compound, which is prepared from erythromycin A through acetylation of the hydroxyl at position 2', formulation and hemiketalization of the hydroxyl at position 4", oxidation of the hydroxyl at position 11, alkylation of the hydroxyl at position 12 and removal of the acetyl at position 2' and the formyl at position 4", with benzyloxycarbonyl chloride under basic conditions, freeing the obtained compound from the benzyloxycarbonyl group thus introduced, alkylating the nitrogen atom at position 3', converting the obtained compound into a fumaric acid salt, recrystallizing the obtained crude salt from an alcoholic solvent, and recrystallizing the obtained crystal from hydrous ethyl acetate again.
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