反应详情

N,N-Dimethylformamide (0.19 g.), phosphorylchloride (0.40 g.), 2-(2-formamidothiazol-4-yl)-2-(2-tert-butoxycarbonylaminoethoxyimino)acetic acid (syn isomer, 0.72 g.) and ethyl acetate (8.5 ml.) were treated in a similar manner to that of Example 1-(1) to give an activated acid solution. The solution was added to a solution of 7-amino-3-cephem-4-carboxylic acid (0.40 g.), trimethylsilylacetamide (1.35 g.), and bis(trimethylsilyl)acetamide (1.2 ml.) in ethyl acetate (4 ml.) at -10° C., and stirred at the same temperature for 1.5 hours. Water (10 ml.) and ethyl acetate (7 ml.) were added to the resultant solution, and the ethyl acetate layer was separated, extracted with a saturated aqueous solution of sodium bicarbonate (10 ml.). The extract was adjusted to pH 5.0 with 85% phosphoric acid and extracted with ethyl acetate (50 ml.). The extract was dried over magnesium sulfate and concentrated in vacuo to give 7-[2-(2-formamidothiazol-4-yl)-2-(2-tertbutoxycarbonylaminoethoxyimino)acetamido]-3-cephem-4-carboxylic acid (syn isomer, 0.65 g.).

1. customto give an activated acid solution
2. customthe ethyl acetate layer was separated
3. extractionextracted with a saturated aqueous solution of sodium bicarbonate (10 ml.)
4. extractionextracted with ethyl acetate (50 ml.)
5. dry with materialThe extract was dried over magnesium sulfate
6. concentrationconcentrated in vacuo