反应详情

To a solution of ethyl 5-[(2′-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-1′(2′H)-yl)methyl]-2-(trifluoromethyl)furan-3-carboxylate (1.30 g, 2.59 mmol) in ethanol (8 mL) and water (1.7 mL) was added sodium hydroxide (0.12 g, 3.00 mmol). The reaction mixture was heated at reflux for 45 min, concentrated in vacuo to remove ethanol. To the residue was added water (15 mL) and the mixture was acidified to pH˜3 by 10% hydrochloric acid at 0° C. The resulting mixture was extracted with ethyl acetate (3×50 mL). The organic layer was washed with water and brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to give 5-((2′-oxo-6H-spiro[benzofuro[6,5-d][1,3]dioxole-7,3′-indoline]-1′-yl)methyl)-2-(trifluoromethyl)furan-3-carboxylic acid (1.03 g, 84%): mp 195-197° C.; 1H NMR (300 MHz, DMSO-d6) δ 7.13-7.26 (m, 1H), 7.17-7.15 (m, 2H), 7.05-7.00 (m, 2H), 6.67 (s, 1H), 6.09 (s, 1H), 5.90-5.88 (m, 2H), 5.11-4.96 (m, 2H), 4.80-4.66 (m, 2H); 13C NMR (75 MHz, DMSO-d6) δ 177.0, 161.9, 155.8, 152.3, 148.9, 142.2, 141.9, 141.5, 132.1, 129.3, 124.1, 123.8, 122.2, 120.6, 120.1, 117.0, 111.8, 109.7, 103.1, 101.9, 93.8, 80.1, 57.9, 36.7; MS (ES−) m/z 472.0 (M−1).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 45 min
3. concentrationconcentrated in vacuo
4. customto remove ethanol
5. additionTo the residue was added water (15 mL)
6. customwas acidified to pH˜3 by 10% hydrochloric acid at 0° C
7. extractionThe resulting mixture was extracted with ethyl acetate (3×50 mL)
8. washThe organic layer was washed with water and brine
9. dry with materialdried over anhydrous sodium sulfate
10. filtrationfiltered
11. concentrationThe filtrate was concentrated in vacuo