反应详情

One adds triethylamine (5.68 ml) to a stirred suspension of p-nitrobenzyl α-[3-benzyl-7-oxo-4-thia-2,6-diazabicyclo[3,2,0]hept-2-en-6-yl]-α-(1-hydroxyethylidene)acetate (9.06 g) in tetrahydrofuran (120 ml) under nitrogen atmosphere at -20° C to give clear solution, adds methanesulfonyl chloride (1.65 ml) to the solution, stirs for 30 minutes at the same temperature, adds morpholine (1.92 ml), warms to 0° C, stirs for 5 hours, cools to -30° C, adds pyridine (1.54 ml) and bromine (3.12 g), stirs for 20 minutes, warms to ice-water temperatur, adds 5% hydrochloric acid (144 ml) and methanol (120 ml), stirs for 3 hours at room temperature, and lets stand overnight at 0° C. Collection of the separated crystals in the reaction mixture by filtration gives p-nitrobenzyl 7-phenylacetamido-3-hydroxy-3-cephem-4-carboxylate (6.678 g). m.p. 201° C. Yield: 71 %.

1. customto give clear solution
2. customwarms to 0° C
3. waitstirs for 20 minutes
4. waitstirs for 3 hours at room temperature
5. waitlets stand overnight at 0° C
6. customCollection of the separated crystals in the reaction mixture
7. filtrationby filtration