Hydrochloric Acid → 7'-(trifluoromethyl)spiro[furo[2,3-f][1,3]benzodioxole-7,3'-indol]-2'(1'H)-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(6-hydroxy-1,3-benzodioxol-5-yl)-3-(hydroxymethyl)-7-(trifluoromethyl)-1,3-dihydro-2H-indol-2-one (4.10 g, 11.7 mmol) in ethyl acetate (100.0 mL) was added tributylphosphine (3.4 mL, 2.83 g, 13.9 mmol) at 0° C. followed by the solution of di-tert-butyl azodicarboxylate (3.22 g, 13.9 mmol) in ethyl acetate (50.0 mL). The reaction solution was stirred at 0° C. for 30 min followed by the addition of 10% hydrochloric acid (50.0 mL). The reaction solution was washed with 10% hydrochloric acid (2×50.0 mL), saturated ammonium chloride (3×50 mL) and brine (3×50 mL). The organic solution was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was purified by flash chromatography to afford 7′-(trifluoromethyl)spiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one (3.59 g, 88%): mp 245-248° C.; 1H NMR (300 MHz, DMSO-d6) δ 11.02 (s, 1H), 7.50 (d, J=7.9 Hz, 1H), 7.36 (d, J=7.3 Hz, 1H), 7.11 (dd, J=7.5, 7.5 Hz, 1H), 6.66 (s, 1H), 6.32 (s, 1H), 5.90 (d, J=3.1 Hz, 2H), 4.74 (ABq, 2H); 13C NMR (75 MHz, DMSO-d6) δ 179.4, 156.0, 148.9, 139.7, 134.9, 128.3, 125.8, 125.7 (m), 122.9, 119.7, 112.0, 111.4 (m), 103.6, 101.9, 93.7, 80.4, 57.5; MS (ES+) m/z 350.3 (M+1).

Provenance & Evidence