反应详情

To a stirred solution of ethyl 3-hydroxy-1-methyl-1H-pyrazole-5-carboxylate (10 g, 58.8 mmol), 2-(dimethylamino)ethanol (5.76 g, 64.7 mmol) and PPh3 (21.6 g, 82.3 mmol) in anhydrous THF (200 mL) was added dropwise DIAD (16.6 g, 82.3 mmol) at 0° C. After the addition, the reaction mixture was stirred at rt overnight. The reaction mixture was concentrated in vacuo and the residue was purified by column chromatography on silica gel (CH2Cl2/MeOH 30:1) to give the title compound (5.6 g, 40% yield) as a brown oil.

1. additionAfter the addition
2. concentrationThe reaction mixture was concentrated in vacuo
3. customthe residue was purified by column chromatography on silica gel (CH2Cl2/MeOH 30:1)