反应详情

Sodium 7-[2-(2-aminothiazol-4-yl)acetamido]-3-vinyl-3-cephem-4-carboxylate (1.36 g), which was prepared from 7-[2-(2-aminothiazol-4-yl)acetamido]-3-vinyl-3-cephem-4-carboxylic acid (1.33 g) and sodium bicarbonate (0.304 g), was dissolved in N,N-dimethylformamide (14 ml). To this solution was added iodomethyl pivalate (0.932 g) in N,N-dimethylformamide (3 ml) under ice-cooling, followed by stirring at the same temperature for 10 minutes. After addition of ethyl acetate (80 ml), the reaction mixture was washed twice with water, three times with 5% aqueous solution of sodium bicarbonate and twice with an aqueous solution of sodium chloride in turn, dried over anhydrous magnesium sulfate, and then evaporated to dryness under reduced pressure to give a residue, which was pulverized with diisopropyl ether to obtain pivaloyloxymethyl 7-[2-(2-aminothiazol-4-yl)acetamido]-3-vinyl-3-cephem-4-carboxylate (1.0 g), mp 128°-132° C. (dec.).

1. temperaturecooling
2. washthe reaction mixture was washed twice with water, three times with 5% aqueous solution of sodium bicarbonate and twice with an aqueous solution of sodium chloride in turn
3. dry with materialdried over anhydrous magnesium sulfate
4. customevaporated to dryness under reduced pressure
5. customto give a residue, which