反应详情

A mixture of 1-benzyl-3-(5-methoxycarbonyl-2-furyl)-1H-indazole (1.46 g, 4.39 mmol), 15% aqueous KOH solution (100 mL) and methanol (100 mL) was heated to reflux for 4 h. The resultant solution was allowed to cool and then diluted with H2O (300 mL). The solution was acidified to pH 2 by the addition of conc. HCl and the precipitate collected by vacuum filtration. The off-white solid was washed with H2O and air dried. Recrystallisation of the crude solid (EtOH) gave the product as fine off-white needles (1.16 g, 83%): mp 205-206.5° C. (lit mp 200-202° C.); 1H-NMR (DMSO) 5.34 (s, 2H), 6.67 (d, 1H, J 3.6 Hz), 6.89-7.00 (m, 7H), 7.08 (m, 2H), 7.89 (d, 1H, J 8.0 Hz); 13C-NMR (CDCl3) 52.55, 109.06, 110.91, 119.84, 120.91, 121.22, 122.57, 127.49, 127.69 (2C), 128.02, 128.99(2C), 134.69, 137.40, 140.72, 144.41, 151.75, 159.67; MS (EI) M+; Anal. (C19H14N2O3) C, calcd 73.19; found 73.18, H, calcd 7.17; found 7.16, N, calcd 14.23; found 14.13.

1. temperaturewas heated
2. temperatureto reflux for 4 h
3. temperatureto cool
4. filtrationthe precipitate collected by vacuum filtration
5. washThe off-white solid was washed with H2O and air
6. customdried
7. customRecrystallisation of the crude solid (EtOH)