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

Participants

Reaction Steps

To a solution of 1-(diphenylmethyl)-3-(6-hydroxy-1,3-benzodioxol-5-yl)-5-methyl-1,3-dihydro-2H-indol-2-one (1.61 g, 3.60 mmol) and para-formaldehyde (0.43 g, 14.6 mmol) in dichloromethane (60.0 mL) was added diisopropylamine (7.20 mmol). After stirring at ambient temperature for 3 h, the reaction was quenched with saturated aqueous ammonium chloride (60.0 mL). The organic layer was separated and washed with water (3×100 mL), dried over sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was subjected to column chromatography eluting with ethyl acetate/hexanes (20-60%) to afford the title compound (1.07 g, 63%) as a colorless solid: 1H NMR (300 MHz, CDCl3) δ 10.09 (br, 1H), 7.37-7.16 (m, 12H), 6.99 (s, 1H), 6.87 (d, 1H), 6.62 (s, 1H) 6.54 (s, 1H), 6.37 (d, 1H), 5.87 (d, 2H), 4.45 (ABq, 2H), 2.33 (s, 3H); MS (ES+) m/z 480.4 (M+1).

Provenance & Evidence