反应详情

To a mixture of ethyl 6-(2-ethoxy-1-hydroxy-2-oxoethyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidine-2-carboxylate (3.7 g, 6.41 mmol) in CH2Cl2 (80 mL) was added Dess-Martin Periodinane (2.72 g, 6.41 mmol) and the resulting mixture was stirred at rt for 1 h. The reaction mixture was diluted with ethyl acetate (500 mL) and washed with sat. aq. NaHCO3 solution (100 mL), dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (5-70% EtOAc/hexane) to afford the desired ethyl 6-(2-ethoxy-2-oxoacetyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidine-2-carboxylate (2.5 g, 5.8 mmol, 91% yield) as an off-white solid. 1H NMR (400 MHz, CDCl3) δ 7.36 (s, 1H), 4.50 (dq, J=14.5, 7.1 Hz, 4H), 2.56 (s, 3H), 1.46 (t, J=7.2 Hz, 3H), 1.48 (t, J=7.2 Hz, 3H). LCMS (M+H)=431.87.

1. washwashed with sat. aq. NaHCO3 solution (100 mL)
2. dry with materialdried (Na2SO4)
3. filtrationfiltered
4. concentrationconcentrated in vacuo
5. customThe residue was purified by silica gel chromatography (5-70% EtOAc/hexane)