反应详情

温度

80 °C

1H-indazole-5-carbonitrile (D1) (3.5 g, 24.45 mmol) was dissolved in N,N-dimethylformamide (60 ml). cesium carbonate (15.93 g, 48.9 mmol) and ethyl 3-bromopropanoate (4.68 ml, 36.7 mmol) were added. The mixture was heated at 80° C. for 4 hours. Diluted with EtOAc and washed with water (3×40 ml), dried over MgSO4 and evaporated. The mixture was purified by flash chromatography, eluting EtOAc/iso-Hexane 10-30% then 10-20% to give (3.682 g) for the first isomer (yellow oil) and (1.509 g) for the second isomer (pink solid). Analysis of the first isomer by 1H nmr indicated that is was the 1-isomer contaminated with the 2-isomer (ca. 20%) δH (d6-DMSO, 400 MHz) 1.05 (3H, t), 2.95 (2H, t), 3.97 (2H, q), 4.69 (2H, t), 7.74 (1H, dd), 7.92 (1H, dt), 8.28 (1H, d), 8.38 (1H, dd). MS (ES+): C13H13N3O2 requires 243; found (MH+) 244.

1. washwashed with water (3×40 ml)
2. dry with materialdried over MgSO4
3. customevaporated
4. customThe mixture was purified by flash chromatography
5. washeluting EtOAc/iso-Hexane 10-30%
6. custom10-20% to give (3.682 g) for the first isomer (yellow oil) and (1.509 g) for the second isomer (pink solid)