反应详情

To a mixture of ethyl 1H-pyrazole-4-carboxylate (35.0 g, 250 mmol) and K2CO3 (69.0 g, 500 mmol) in CH3CN (250 mL) was added BnBr (42.7 g, 250 mmol). The mixture was stirred at RT for 18 h and concentrated. The residue was suspended in EA (500 mL), washed with water (200 mL×2), dried over Na2SO4 and concentrated to give the desired compound as a white solid (53.0 g, 91.2%). 1H NMR (DMSO-d6) δ 8.46 (s, 1H), 7.88 (s, 1H), 7.41-7.19 (m, 5H), 5.37 (s, 2H), 4.21 (q, 2H, J=5.4 Hz), 1.25 (t, 3H, J=5.4 Hz). MS (ESI) m/e [M+1]+ 231.0.

1. concentrationconcentrated
2. washwashed with water (200 mL×2)
3. dry with materialdried over Na2SO4
4. concentrationconcentrated