Dichloromethane → 5-(1H-indol-2-yl)-2,4-dimethoxybenzaldehyde

Participants

Reaction Steps

Ex-32B: 2-(5-Formyl-2,4-dimethoxyphenyl)indole-1-carboxylic acid tert-butyl ester (Ex-32A, 2.0 g, 5.2 mmol) was dissolved in 100 ml of THF, and Bu4NF (6.86 g, 26 mmol) was added. The reaction mixture was stirred at room temperature overnight. No significant reaction occurred under these conditions by HPLC. Then, additional Bu4NF (6.86 g, 26 mmol) was added to the mixture, and the mixture was stirred at reflux for 4 days. The reaction reached about 50% completion (HPLC). The reaction mixture was poured into CH2Cl2, and washed with water and brine. The organic phase was dried over MgSO4, and concentrated. The residue was purified by column chromatography (EtOAc/hexanes, 2:1) to give 0.45 g (30%) of 5-(1H-indol-2-yl)-2,4-dimethoxybenzaldehyde. 1H-NMR (300 MHz, CDCl3) δ 10.37 (s, 1H), 9.25 (br, 1H), 8.28 (s, 1H), 7.63(d, J=8 Hz, 1H), 7.39 (d, J=8 Hz, 1H), 7.08–7.20 (m, 2H), 6.92(d, J=2 Hz, 1H), 6.56 (s, 1H) 4.11(s, 3H), 4.00 (s, 3H). HMRS (EI) calcd. for C17H15NO3: 281.1052 (M+); Found: 281.1049.

Provenance & Evidence