反应详情

Under ice-cooling and stirring, 6 ml of an aqueous solution containing 288 mg of cis-3-amino-2-oxoazetidine-4-carboxylic acid methyl ester and 561 mg of sodium hydrogen carbonate is added to a suspension of 1.18 g of 2-(2-chloroacetamido-4-thiazolyl)-2-methoxyiminoacetyl chloride (syn isomer) in 10 ml of tetrahydrofuran. After the mixture is stirred for 2 hours at room temperature, the solvent is distilled off in vacuo to leave a residue, which solidifies. Water is added to the solid, followed by filtration, and the collected crystals are washed successively with water and ethanol to give cis-3-[2-(2-chloroacetamido-4-thiazolyl)-2-methoxyiminoacetamido]-2-oxoazetidine-4-carboylic acid methyl ester (syn isomer), m.p. 270°-275° C. (dec.).

1. temperatureUnder ice-cooling
2. stirringAfter the mixture is stirred for 2 hours at room temperature
3. distillationthe solvent is distilled off in vacuo
4. customto leave a residue, which
5. filtrationfollowed by filtration
6. washthe collected crystals are washed successively with water and ethanol