反应详情

温度

5 °C

To a mixture of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-[(Z)-1-butenyl]-3-cephem-4-carboxylic acid (1.55 g, 3.54 mmoles) and K2CO3 (636 mg, 4.6 mmoles) in DMF (4 ml) was added at 5° C. 1-bromoethyl acetate (769 mg, 4.6 mmoles). The mixture was stirred at 5° C. for 1 hour, diluted with ethyl acetate (300 ml), washed with water, dried over anhydrous MgSO4 and concentrated in vacuo. The residue was dissolved in chloroform and chromatographed on a silica gel column (50 g) with 1% methanol in CHCl3. The desired fractions were combined and concentrated to a small volume. The resdiue was triturated with isopropyl ether to give 1.29 g (70%) of the title compound as the isopropyl ether solvate. Estimated purity 90% (by HPLC). Mp. 103°-110° C. (dec.).

1. additionwas added at 5° C
2. washwashed with water
3. dry with materialdried over anhydrous MgSO4
4. concentrationconcentrated in vacuo
5. dissolutionThe residue was dissolved in chloroform
6. customchromatographed on a silica gel column (50 g) with 1% methanol in CHCl3
7. concentrationconcentrated to a small volume
8. customThe resdiue was triturated with isopropyl ether