反应详情

To 35 ml of dimethyl formamide is added 7.5 g of the sodium salt of 3-[(acetyloxy)methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0 ]oct-2-ene-2-carboxylic acid, and the solution is stirred at room temperature for about 30 minutes after which 8 ml of chloromethylpivalate is added. Stirring is continued at room temperature for about 3 hours. The mixture is diluted with ethyl acetate and washed with water. The organic layer is separated and evaporated to dryness. The residue is recrystallized from ethyl acetate to give 3-[(acetyloxy)methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid pivalyloxymethyl ester.

1. additionis added
2. washwashed with water
3. customThe organic layer is separated
4. customevaporated to dryness
5. customThe residue is recrystallized from ethyl acetate