Potassium Phosphate, Dibasic → 7-(4-Methoxyphenyl)-benzofuran-4-carbaldehyde

Participants

Reaction Steps

To a solution of 7-(4-methoxyphenyl)-4-methylbenzofuran (1.27 g, 5.34 mmol) in carbon tetrachloride (150 ml) was added NBS (1.05 g, 5.87 mmol) and AIBN (50 mg). The solution was brought to reflux for 2 h, cooled to room temperature, and the solids were filtered off. The solution was then concentrated and anhydrous CH3CN (50 ml) was added. Then potassium benzeneselenite (Syper, Ludwik; Mlochowski, Jacek Synthesis 1984, 9, 747–752) (1.33 g, 5.87 mmol), and K2HPO4 (0.93 g, 5.34 mmol) were added and the reaction was heated to reflux for 1 h after which it was allowed to cool to room temperature. The solution was then passed through a silica plug and the plug was washed with 30% EtOAc/hexanes after which the CH3CN was stripped off under hi vacuum. Chromatography (100% CH2Cl2) removed the Ph2Se2 by-product to afford 1.0 g (75%) of product as a white solid: mp 143–144° C.; 1H NMR (300 MHz, DMSO-d6): δ 3.85 (3H, s), 7.15 (2H, d, J=8.7 Hz), 7.57 (1H, d, J=2.1 Hz), 7.75 (1H, d, J=7.8 Hz), 7.96 (3H, appt), 8.33 (1H, d, J=2.1 Hz), 8.04 (1H, d, J=2.2 Hz); MS (ESI) m/z 253 ([M+H]+).

Provenance & Evidence