反应详情

A solution of 4.2 g. (20 mmol) of 3,5-diacetoxymethylpyrazole in 15 ml. of DMF was added dropwise to a suspension of 960 mg. (20 mmol) of NaH (50% in mineral oil) in 25 ml. of DMF stirred at 0° and under argon. After the evolution of H2 had ceased, 4.9 g. (20 mmol) of 2-fluoro-5-nitrobenzophenone was added in one portion. After stirring at 0° for 4 hours, the mixture was poured into ice-water and extracted with EtOAc. The organic phase was washed with dil. brine, dried (MgSO4) and concentrated. The residue was chromatographed on silica gel using benzene/EtOAc (1:1) as eluent. Removal of the solvents gave crude end product as a gum which was not purified further. The nmr (CDCl3) had signals at: δ2.00 (3H, s, CH3), 2.07 (3H, s, CH3), 4.82 (2H, s, CH2), 5.10 (2 H, s, CH2) 6.33 (1H, s, C=CH), and 7.30-8.67 (8H, m, C6H5 + C6H3).

1. extractionextracted with EtOAc
2. washThe organic phase was washed with dil. brine
3. dry with materialdried (MgSO4)
4. concentrationconcentrated
5. customThe residue was chromatographed on silica gel
6. customRemoval of the solvents
7. customgave crude end product as a gum which
8. customwas not purified further