反应详情

1.30 g of sodium borohydride are added in portions to a solution of 35.4 g of 3-hydroxy-7β-phenoxyacetylamino-3-cephem-4-carboxylic acid diphenylmethyl ester (crude product) in a mixture of 270 ml of dimethylformamide and 70 ml of glacial acetic acid in a stream of nitrogen while stirring and cooling with ice at approximately 15° to 20°. The reaction mixture is further stirred for one hour at room temperature, poured onto a mixture of ice and 2 N hydrochloric acid and extracted with ethyl acetate. The organic phase is washed successively with 2 N hydrochloric acid, water, saturated, aqueous sodium bicarbonate solution and saturated, aqueous sodium chloride solution, dried over sodium sulphate and concentrated in vacuo. The residue is substantially freed from dimethylformamide under a high vacuum and recrystallised from ethyl acetate and a little diethyl ether. The title compound is obtained which has a melting point of 167°-170°; Rf~0.47 (silica gel; toluene/ethyl acetate 1:1); [α]D20 =+88°± 1° (in chloroform, c=0.526%); IR spectrum (in CH2Cl2): Absorption bands up to 3580; 3410; 1780; 1740; 1695; 1600; 1518; 1494 cm-1.

1. temperaturecooling with ice at approximately 15° to 20°
2. stirringThe reaction mixture is further stirred for one hour at room temperature
3. extractionextracted with ethyl acetate
4. washThe organic phase is washed successively with 2 N hydrochloric acid, water
5. dry with materialsaturated, aqueous sodium bicarbonate solution and saturated, aqueous sodium chloride solution, dried over sodium sulphate
6. concentrationconcentrated in vacuo
7. customrecrystallised from ethyl acetate