反应详情

1 ml of pyridine and 0.5 ml of phenylacetic acid chloride are added at 0° C, under a nitrogen atmosphere, to a suspension of 0.250 g of 7β-amino-3-methoxy-3-cephem-4-carboxylic acid diphenylmethyl ester in 25 ml of methyl chloride and the mixture is stirred for 30 minutes at this temperature. The reaction mixture is evaporated under reduced pressure; the residue is stirred for 10 minutes with 20 ml of a 1:1 mixture of dioxane and water and diluted with methylene chloride. The aqueous phase is separated off and extracted with methylene chloride. The combined organic phases are washed with a saturated aqueous sodium bicarbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulphate and evaporated under reduced pressure. The crude product is purified by means of preparative thin layer chromatography using, as the solvent, a 1:1 mixture of toluene and ethyl acetate. The zone visible under ultraviolet light of λ = 254 mμ (Rf~0.35) is eluted with a 4:1 mixture of acetone and methanol and gives 3-methoxy-7β-(α-phenylacetylamino)-3-cephem-4-carboxylic acid diphenylmethyl ester which is identical with the product obtainable by the process of Example 9.

1. customThe reaction mixture is evaporated under reduced pressure
2. stirringthe residue is stirred for 10 minutes with 20 ml of a 1:1 mixture of dioxane and water
3. additiondiluted with methylene chloride
4. customThe aqueous phase is separated off
5. extractionextracted with methylene chloride
6. washThe combined organic phases are washed with a saturated aqueous sodium bicarbonate solution
7. dry with materiala saturated aqueous sodium chloride solution, dried over sodium sulphate
8. customevaporated under reduced pressure
9. customThe crude product is purified by means of preparative thin layer chromatography
10. additiona 1:1 mixture of toluene and ethyl acetate
11. washThe zone visible under ultraviolet light of λ = 254 mμ (Rf~0.35) is eluted with a 4:1 mixture of acetone and methanol