反应详情

温度

70 °C

A suspension of 5-methoxy-1H-indazole-3-carboxylic acid (21.5 g; 0.11 mol) and 60% NaH (10.5 g; 0.44 mol) in N,N-dimethylformamide (DMF) (200 ml) was stirred at 70° C. for 1 hour. Benzyl chloride (32.9 g; 0.26 mol) was then added slowly to the suspension and the mixture was stirred at 70° C. for 4 hours. The reaction was stopped by cooling the mixture to room temperature and pouring the mixture into water and ice. The product was extracted with ethyl acetate (3×250 ml). The combined organic phases were concentrated under reduced pressure. The crude residue thus obtained was purified by successive crystallizations from 95° ethanol, to give 18 g of benzyl 1-benzyl-5-methoxy-1H-indazole-3-carboxylate with a melting point of 107-109° C.

1. stirringthe mixture was stirred at 70° C. for 4 hours
2. temperatureby cooling the mixture to room temperature
3. extractionThe product was extracted with ethyl acetate (3×250 ml)
4. concentrationThe combined organic phases were concentrated under reduced pressure
5. customThe crude residue thus obtained
6. customwas purified by successive crystallizations from 95° ethanol