反应详情

温度

22 °C

A mixture of intermediate 3, ethyl 5-benzyloxy-1-(methoxycarbonylmethyl)-2-(methylsulfonyl)-6-oxo-1,6-dihydropyrimidine-4-carboxylate, (0.487 g, 1.15 mmol) in N,N-dimethylformamide (25 ml) was treated with 1,2-dimethylhydrazine dihydrochloride (1.56 g, 11.7 mmol) followed by N,N-diisopropylethylamine (4.1 ml, 11.7 mmol) and the resulting mixture stirred at 22° C. for 4 h. The solvent was then removed in vacuo and the residue diluted with ethyl acetate, washed successively with saturated sodium bicarbonate and brine then dried over anhydrous magnesium sulfate. Evaporation of the solvent followed by chromatography on silica gel (elution with a gradient of ethyl acetate 0–50% in toluene) gave 0.294 g (69% yield) of the title ester as a clear syrup.

1. customThe solvent was then removed in vacuo
2. additionthe residue diluted with ethyl acetate
3. washwashed successively with saturated sodium bicarbonate and brine
4. dry with materialthen dried over anhydrous magnesium sulfate
5. customEvaporation of the solvent
6. washelution with a gradient of ethyl acetate 0–50% in toluene)