反应详情

A solution of 2-(1H-indazol-3-yl)acetic acid (300 mg, 1.70 mmol) in methanol (15 mL) containing 5 drops of concentrated sulfuric acid was refluxed for 14 hours. The reaction mixture was concentrated under reduced pressure to a low volume, and then diluted with ethyl acetate (8 mL). The organic layer was treated with water (2×5 mL) and 10% sodium bicarbonate solution (5 mL). The ethyl acetate phase was collected, dried over sodium sulfate and concentrated to quantitatively obtain the title compound as crystalline solid upon drying at high vacuum. C10H10N2O2, Mr=190.20; 1H NMR (400 MHz, DMSO-d6) d: 3.62 (s, 3H), 4.01 (s, 2H), 7.09 (td, J=0.8/7.4 Hz, 1H), 7.33 (td, J=1.0/7.7 Hz, 1H), 7.48 (d, J=8.4 Hz, 1H), 7.69 (d, J=8.4 Hz, 1H); 13C NMR (100 MHz, DMSO-d6) d: 33.04 (s, —CH2—), 52.17 (s, —OCH3), 110.49 (s, C7′), 120.29 (s), 120.43 (s), 122.20 (s, C4a′), 126.40 (s, C6′), 138.83 (s, C7a′), 141.20 (s, C3′), 171.03 (s, >C═O); LCMS (ESI) tR: 1.65 min (>99%, UV254), m/z: 191.2 [M+1]+.

1. temperaturewas refluxed for 14 hours
2. concentrationThe reaction mixture was concentrated under reduced pressure to a low volume
3. additiondiluted with ethyl acetate (8 mL)
4. additionThe organic layer was treated with water (2×5 mL) and 10% sodium bicarbonate solution (5 mL)
5. customThe ethyl acetate phase was collected
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated