Formaldehyde → 3-(6-hydroxy-1,3-benzodioxol-5-yl)-3-(hydroxymethyl)-7-(trifluoromethyl)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of 3-(6-hydroxy-1,3-benzodioxol-5-yl)-7-(trifluoromethyl)-1,3-dihydro-2H-indol-2-one (5.64 g, 16.7 mmol), para-formaldehyde (1.78 g, 59.4 mmol) in tetrahydrofuran (20.0 mL) and water (50.0 mL) was added the aqueous solution of sodium hydroxide (2.68 g, 66.9 mmol) in water (30.0 mL). The reaction mixture was stirred at 0° C. for 1 h and quenched with 10% hydrochloric acid (50.0 mL). The mixture was extracted with ethyl acetate (3×50.0 mL). The combined organic solution was washed with saturated ammonium chloride (3×50 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was purified by column chromatography to afford 3-(6-hydroxy-1,3-benzodioxol-5-yl)-3-(hydroxymethyl)-7-(trifluoromethyl)-1,3-dihydro-2H-indol-2-one (4.56 g, 73%) as a fluffy solid: 1H NMR (300 MHz, DMSO-d6) δ 10.63 (s, 1H), 9.16 (s, 1H), 7.32 (d, J=7.9 Hz, 1H), 7.08 (d, J=7.2 Hz, 1H), 7.01 (s, 1H), 6.94 (dd, J=7.7, 7.7 Hz, 1H), 6.18 (s, 1H), 5.88 (s, 2H), 5.03 (br, 1H), 3.97 (ABq, J=9.9 Hz, 2H); 13C NMR (75 MHz, DMSO-d6) δ 180.5, 150.3, 146.8, 141.5, 140.0, 136.0, 127.5, 123.8, 121.0, 117.7, 109.7, 108.4, 101.2, 97.9, 60.2, 55.2; MS (ES+) m/z 390.2 (M+1).

Provenance & Evidence