反应详情

A mixture of 7-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn isomer, 6.0 g) and molecular sieves (20 g) in dry pyridine (60 ml) was stirred at 0° to 5° C. for an hour, and 2-n-octyloxy-1-n-octyloxymethylethanol [4.6 g] was added thereto. Benzenesulfonyl chloride (2.6 g) was dropwise added to the stirred solution at -5° to -3° C. over 30 minutes, and then stirred at 0° C. for an hour. The resultant mixture was poured into the crushed ice (300 g), adjusted to pH 1 to 2 with 20% sulfuric acid, and then extracted with ethyl acetate (300 ml). The extract was washed with a saturated aqueous solution of sodium chloride, an aqueous solution of sodium bicarbonate and a saturated aqueous solution of sodium chloride in turn, and dried over anhydrous magnesium sulfate. The solution was evaporated under reduced pressure, and the residue was subjected to column chromatography on silica gel (200 g) with a mixture of chloroform and methanol (20:1). The eluate was evaporated in vacuo to give powder [3.1 g] of 2-n-octyloxy-1-n-octyloxymethylethyl 7-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-2-cephem-4-carboxylate (syn isomer).

1. stirringstirred at 0° C. for an hour
2. extractionextracted with ethyl acetate (300 ml)
3. washThe extract was washed with a saturated aqueous solution of sodium chloride
4. dry with materialan aqueous solution of sodium bicarbonate and a saturated aqueous solution of sodium chloride in turn, and dried over anhydrous magnesium sulfate
5. customThe solution was evaporated under reduced pressure
6. additionthe residue was subjected to column chromatography on silica gel (200 g) with a mixture of chloroform and methanol (20:1)
7. customThe eluate was evaporated in vacuo