反应详情

A stirred solution of 2-(2-tritylaminothiazol-4-yl)-2-(Z)-(t-butyloxycarbonyl)methoxyiminoacetic acid (498 mg) in dimethylformamide (4 ml) was cooled to -55° C. to -60° C. and N,N-diisopropylethylamine (0.157 ml) was added, followed by methanesulphonyl chloride (0.068 ml). The mixture was stirred at the same temperature for 0.5 h and then diphenylmethyl 7β-amino-3-(2,5-dihydro-2-oxofuran-4-ylthiomethyl)ceph-3-em-4-carboxylate (395 mg) and pyridine (0.064 ml) were added. The mixture was then stirred at 0° for 1.25 h, and then partitioned between ethyl acetate and citric acid solution. The organic phase was washed successively with water, sodium bicarbonate solution, water and brine. The solution was dried over magnesium sulphate and evaporated. The product (567 mg) was isolated by column chromatography of the residue using gradient elution (Kieselgel 1:1 going to 3:7 hexane: ethyl acetate as eluent). υmax (CHCl3) 3400, 3250, 1790, 1745, 1730 and 1680cm-1 ; δ(CDCl3) 1.43 (9H, s), 3.40 (1H, d, J 18.0Hz), 3.56 (1H, d, J 18.0Hz), 3.91 (1H, d, J 12.4Hz), 4.02 (1H, d, J 12.4Hz), 4.72 (2H, s), 4.73 (1H, d, J 17.1Hz), 4.81 (1H, d, J 17.1Hz), 5.08 (1H, d, J 4.9Hz), 5.66 (1H, s), 5.93 (1H, dd, J 4.9 and 8.3Hz), 6.82 (1H, s), 6.95 (1H, s,), 7.01 (1H, s), 7.2-7.45 (25H, m), 8.77 (1H, d, J 8.3Hz).

1. stirringThe mixture was then stirred at 0° for 1.25 h
2. custompartitioned between ethyl acetate and citric acid solution
3. washThe organic phase was washed successively with water, sodium bicarbonate solution, water and brine
4. dry with materialThe solution was dried over magnesium sulphate
5. customevaporated