反应详情

In N,N-dimethylformamide (20 ml) was dissolved 7β-(2-thienylacetamido-)-3-hydroxymethyl-3-cephem-4-carboxylic acid sodium salt (3.86 g) and, at -5° C., triethylamine (1.40 ml) and diketene (1.50 ml) were added. The reaction was carried out at -5°-0° C. for 1 hour, after which time the reaction mixture was poured in ice-water (200 ml). The mixture was adjusted to pH 2.0 with 4 N-hydrochloric acid and extracted with ethyl acetate. The ethyl acetate layer was rinsed with water, diluted with water, brought to pH 7.0 with 5% aqueous sodium hydrogen carbonate solution and separated. The water layer was taken, concentrated and subjected to column-chromatography on Amberlite XAD-2, elution being carried out with water-methanol. The eluate was lyophilized. The above procedure provided 7β-(2-thienylacetamido)-3-(3-oxobutyryloxy)methyl-3-cephem-4-carboxylic acid sodium salt (4.48 g).

1. extractionextracted with ethyl acetate
2. washThe ethyl acetate layer was rinsed with water
3. additiondiluted with water
4. customseparated
5. concentrationconcentrated
6. washsubjected to column-chromatography on Amberlite XAD-2, elution