反应详情

2.28 g of 7-amino-3-formyl-3-cephem-4-carboxylic acid are bisilylated as described in example 19 with 5.4 ml of N,O-bis-(trimethylsilyl)-acetamide, reacted with phenylacetic acid chloride, and then hydrolysed with 0.4 ml of water. The hydrolysed reaction mixture is treated with 1 g of activated charcoal and then filtered. The yellow filtrate is mixed with 20 ml of a 10% solution of diphenyldiazomethane in dichloromethane, and then concentrated to 10 ml in vacuo. The product is precipitated from the residue of evaporation thus obtained by adding 100 ml of n-hexane. 7-phenylactamido-3-formyl-3-cephem-4-carboxylic acid benzhydrylester is thus obtained as a slightly yellowish product. 1H-NMR (60 MHz, d6 -DMSO): 3.15 (ABq, J=18 Hz, 2H, SCH2); 3.55 (s, 2H, --CH2 --CO); 4.9 (d, J=5 Hz, 1H, H-6); 5.90 (dd, J=5 and 8 Hz, 1H, H-7); 6.6 (d, J=8 Hz, 1H, NH); 7.0 (s, 1H, CHPh2); 7.25 and 7.30 (2s, 15H, Ar--H); 9.62 (s, 1H, CH=O).

1. filtrationfiltered
2. additionThe yellow filtrate is mixed with 20 ml of a 10% solution of diphenyldiazomethane in dichloromethane
3. concentrationconcentrated to 10 ml in vacuo
4. customThe product is precipitated from the residue of evaporation
5. customthus obtained