反应详情

In a mixture of 2 ml of tetrahydrofuran and 2 ml of water is dissolved 75 mg of cis-3-amino-4-hydroxymethyl-2-oxoazetidine as obtained in Reference Example 53C and, under ice-cooling and stirring 168 mg of sodium hydrogen carbonate and then 332 mg of 2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-methoxyiminoacetyl chloride hydrochloride are added. The mixture is stirred under ice-cooling for one hour and the reaction mixture is made neutral with aqueous sodium hydrogen carbonate and extracted with ethyl acetate-tetrahydrofuran (2:1). The extract is washed with saturated aqueous sodium chloride and dried over anhydrous magnesium sulfate. The solvent is then distilled off under reduced pressure and, after addition of ethyl acetate-ether (1:2), the crystalline residue is recovered by filtration to give cis-3-[2-(2-chloroacetamido-4-thiazolyl)-2-methoxyiminoacetamido]-4-hydroxymethyl-2-oxoazetidine (syn-isomer) as colorless crystals, m.p. 238°-241° C. (decomp.).

1. customas obtained in Reference Example 53C and, under ice-
2. temperaturecooling
3. temperaturecooling for one hour
4. extractionextracted with ethyl acetate-tetrahydrofuran (2:1)
5. washThe extract is washed with saturated aqueous sodium chloride
6. dry with materialdried over anhydrous magnesium sulfate
7. distillationThe solvent is then distilled off under reduced pressure
8. additionafter addition of ethyl acetate-ether (1:2)
9. filtrationthe crystalline residue is recovered by filtration