反应详情

To a solution of 288 mg of cis-3-amino-2-oxoazetidine-4-carboxylic acid methyl ester in 2 ml of N,N-dimethylacetamide, which is stirred under ice-cooling beforehand, is added 534 mg of mandelic-carbonic anhydride, followed by stirring at room temperature for 30 minutes. The mixture is stirred beforehand under ice-cooling, to which is added dropwise 1.05 ml of chloroacetyl chloride, followed by stirring at room temperature for 3 hours. The reaction mixture is shaken with 100 ml of ethyl acetate and 20 ml of 1N-HCl, then the organic layer is separated. The organic layer is washed with a saturated aqueous solution of sodium chloride (30 ml×3), 20 ml of 1N-NaHCO3 aqueous solution and a saturated aqueous solution of sodium chloride (30 ml×3), successively, dried, and the solvent is evaporated under reduced pressure. The residue is purified by column-chromatography on silica-gel to afford cis-3-(2-chloroacetyloxy-2-phenylacetamido)-2-oxoazetidine-4-carboxylic acid methyl ester.

1. temperaturecooling beforehand
2. stirringThe mixture is stirred beforehand under ice-
3. temperaturecooling, to which
4. stirringby stirring at room temperature for 3 hours
5. customthe organic layer is separated
6. washThe organic layer is washed with a saturated aqueous solution of sodium chloride (30 ml×3), 20 ml of 1N-NaHCO3 aqueous solution
7. dry with materiala saturated aqueous solution of sodium chloride (30 ml×3), successively, dried
8. customthe solvent is evaporated under reduced pressure
9. customThe residue is purified by column-chromatography on silica-gel