Dibromomethane → Piperonal

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3,4-dihydroxybenzaldehyde (10 g, 72.40 mmol, 1.00 equiv) in DMF (150 mL) was added cesium carbonate (35.4 g, 108.31 mmol, 1.50 equiv) and dibromomethane (18.7 g, 107.57 mmol, 1.50 equiv). The resulting solution was stirred for 2 h at 110° C. The solution was cooled to room temperature and the solid was removed by filtration. The filtrate was diluted with H2O (300 mL). The resulting solution was extracted with EtOAc (2×300 mL). The organic layers were combined, dried over sodium sulfate, and concentrated under reduced pressure. The crude residue was purified by silica gel column chromatography, eluted with with EtOAc/petroleum ether (1:9) to afford 8 g (74%) of the title compound as a yellow solid. 1H-NMR (300 MHz, CDCl3): δ ppm 9.81 (s, 1H), 7.41 (d, J=8.1 Hz, 1H), 7.34 (s, 1H), 6.93 (d, J=8.1 Hz, 1H), 6.08 (s, 2H).

Provenance & Evidence