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US 2009/0221815 A1Published application
Processes for the preparation of cephem derivatives
AssigneeCj Cheiljedang Corporation
InventorsDae Won SEO, In Hwa CHUNG, Ki Bong LEE, In Kyu LEE
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Abstract
Provided is a process for preparing a compound of formula 1 or its salt, which includes reacting a compound of formula 2 with a compound of formula 3 in the presence of a base.
Claims2
A process for stereospecifically preparing a compound represented by the following formula 3a, which comprises a compound represented by the following formula 5 with acetaldehyde in a mixed solvent comprising water, isopropanol, and methylenechloride in a volume ratio of 1:3-6:11-14 in the presence of a base:
- wherein R3 is a hydrogen or a carboxyl protecting group, and R5 is a hydrogen or an amino protecting group.
Dependencies are inferred from the claim text.