反应详情

In a mixture of 17 ml of methylene chloride and 6 ml of N,N-dimethylformamide is dissolved 172 mg of cis-3-[2-(2-chloroacetamido-4-thiazolyl)-2-methoxyiminoacetamido]-4-hydroxymethyl-2-oxoazetidine (syn-isomer), followed by addition of 0.2 ml of pyridine. While the mixture is cooled with ice-sodium chloride mixture and stirred, 0.12 ml of chloroacetyl chloride is added dropwise. The mixture is stirred under cooling for 30 minutes and the solvent is distilled off. To the residue are added aqueous sodium chloride and ethyl acetate, and the mixture is shaken well. The organic layer is separated and washed with aqueous sodium chloride and dried over anhydrous sodium sulfate. The solvent is then distilled off and the residue is crystallized from ether. Recrystallization from chloroform-methanol gives colorless crystals of cis-3-[2-(2-chloroacetamido-4-thiazolyl)-2-methoxyiminoacetamido]-4-chloroacetoxymethyl-2-oxoazetidine (syn-isomer), m.p. 225°-227° C. (decomp.).

1. stirringThe mixture is stirred
2. temperatureunder cooling for 30 minutes
3. distillationthe solvent is distilled off
4. additionTo the residue are added aqueous sodium chloride and ethyl acetate
5. stirringthe mixture is shaken well
6. customThe organic layer is separated
7. washwashed with aqueous sodium chloride
8. dry with materialdried over anhydrous sodium sulfate
9. distillationThe solvent is then distilled off
10. customthe residue is crystallized from ether
11. customRecrystallization from chloroform-methanol