Dibromomethane → Piperonal

Temperature

110 °C

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).

1. temperatureThe solution was cooled to room temperature
2. customthe solid was removed by filtration
3. additionThe filtrate was diluted with H2O (300 mL)
4. extractionThe resulting solution was extracted with EtOAc (2×300 mL)
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe crude residue was purified by silica gel column chromatography
8. washeluted with with EtOAc/petroleum ether (1:9)

ORD record

ord-17b9810e928a4e5ba7125911460a57e7

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181200B2