Method of preparing form II crystals of clarithromycin
US6515116B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2001 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | Mar 14, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.