反应详情

To a stirred mixture of triphenylphosphine (40.7 g) and zinc powder (18.5 g) in methylene chloride (250 ml) was added carbontetrabromide (45 g) at 20°-30° C. Benzhydryl 7-phenylacetamido-3-formyl-2-cephem-4-carboxylate (10 g) was added portionwise to the above reaction mixture, and the mixture was stirred for 30 minutes at room temperature. Triphenylphosphine oxide was solidified by addition of ethyl acetate to the reaction mixture and removed by filtration. The residue left by removal of the solvents was chromatographed on silica gel. The elution with chloroform containing ethyl acetate (10%) gave benzhydryl 7-phenylacetamido-3-(2,2-dibromovinyl)-2-cephem-4-carboxylate (4.4 g).

1. customremoved by filtration
2. waitThe residue left by removal of the solvents
3. customwas chromatographed on silica gel
4. washThe elution with chloroform
5. additioncontaining ethyl acetate (10%)