反应详情

Thiourea (0.14 g.) was added to a solution of 4-nitrobenzyl 7-[2-(2-bromoacetyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylate (syn-isomer: 0.8 g.) in ethanol (20 ml.) and water (5 ml.), and stirred at room temperature for 3.5 hours. The resultant solution was concentrated under reduced pressure, and to the residue were added water and ethyl acetate. The ethyl acetate layer was separated, washed with water, dried over magnesium sulfate and concentrated under reduced pressure to give the crude product (0.6 g.) The product was purified by column chromatography on silica gel (eluent: benzene and ethyl acetate (8:2)) to give 4-nitrobenzyl 7-[2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylate (syn-isomer: 0.21 g.), mp 165° to 170° C. (dec.)

1. concentrationThe resultant solution was concentrated under reduced pressure
2. additionto the residue were added water and ethyl acetate
3. customThe ethyl acetate layer was separated
4. washwashed with water
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customto give the crude product (0.6 g.) The product
8. customwas purified by column chromatography on silica gel (eluent: benzene and ethyl acetate (8:2))