Abstract: The present invention relates to a clathrate of azithromycin hydrate with 1,2-propyleneglycol of formula (I), a method for the manufacture thereof, and a pharmaceutical composition containing same. The inventive compound is much less hygroscopic than azithromycin hydrate or crystals known in the art, therefore, it can be useful for the preparation of a medicine for treating various microbial infections. wherein m ranges from 1 to 2 and n, from 0.30 to 0.45.

Abstract: A clathrate of azithromycin hydrate with 1,2-propyleneglycol is much less hygroscopic than azithromycin hydrate or crystals known in the art, therefore, it can be useful for the preparation of a medicine for treating various microbial infections.

Abstract: Azithromycin is prepared in a high yield by a simple process using a crystalline 9-deoxo-9a-aza-9a-homoerythromycin A hydrate.

Abstract: Clarithromycin can be easily prepared by reacting erythromycin A N-oxide with a methylating agent to obtain 6-O-methylerythromycin A N-oxide; and treating 6-O-methylerythromycin A N-oxide obtained above with a reducing agent in a high yield.

Abstract: A clathrate of azithromycin hydrate with 1,2-propyleneglycol is much less hygroscopic than azithromycin hydrate or crystals known in the art, therefore, it can be useful for the preparation of a medicine for treating various microbial infections.

Abstract: High purity Form II crystals of clarithromycin can be easily prepared in a high yield by a process comprising the steps of: protecting the 9-oxime hydroxy group of erythromycin A 9-oxime or a salt thereof with a tropyl group and the 2′- and 4″-hydroxy groups with trimethylsilyl groups; reacting 2′,4″-O-bis(trimethylsilyl)erythromycin A 9-O-tropyloxime with a methylating agent; removing the protecting groups and the oxime group of 2′,4″-O-bis(trimethylsilyl)-6-O-methylerythromycin A 9-O-tropyloxime to obtain crude clarithromycin; treating the crude clarithromycin with methanesulfonic acid in a mixture of a water-miscible organic solvent and water to obtain crystalline clarithromycin mesylate trihydrate; and neutralizing the crystalline clarithromycin mesylate trihydrate with aqueous ammonia in a mixture of a water-miscible organic solvent and water.

Abstract: Pure Form II crystals of clarithromycin can be prepared by a simple, high-yield process comprising the steps of treating crude clarithromycin or different crystal forms of clarithromycin with formic acid in an organic solvent to obtain crystalline clarithromycin formate and neutralizing the clarithromycin formate with a base in a mixture of water and a water-miscible organic solvent.

Abstract: High purity Form II crystals of clarithromycin can be easily prepared in a high yield by a process comprising the steps of: protecting the 9-oxime hydroxy group of erythromycin A 9-oxime or a salt thereof with a tropyl group and the 2′- and 4″-hydroxy groups with trimethylsilyl groups; reacting 2′,4″-O-bis(trimethylsilyl)erythromycin A 9-O-tropyloxime with a methylating agent; removing the protecting groups and the oxime group of 2′,4″-O-bis(trimethylsilyl)-6-O-methylerythromycin A 9-O-tropyloxime to obtain crude clarithromycin; treating the crude clarithromycin with methanesulfonic acid in a mixture of a water-miscible organic solvent and water to obtain crystalline clarithromycin mesylate trihydrate; and neutralizing the crystalline clarithromycin mesylate trihydrate with aqueous ammonia in a mixture of a water-miscible organic solvent and water.