Dimethyl Sulfoxide → 2-Bromo-4,5-difluorobenzaldehyde

Temperature

0 °C

A solution of (2-bromo-4,5-difluoro-phenyl)-methanol (1.23 g, 5.50 mmol), triethylamine (1.39 g, 13.75 mmol) and dimethyl sulfoxide (1.72 g, 22.00 mmol) in dichloromethane (25 mL) was cooled to 0° C. Then, sulfur trioxide-pyridine (1.32 g, 8.25 mmol) was added portionwise. After one hour stirring at 0° C., a second batch of triethylamine (1.39 g, 13.75 mmol), dimethyl sulfoxide (1.72 g, 22.00 mmol) and sulfur trioxide-pyridine (1.32 g, 8.25 mmol) were added to the above reaction mixture. After another 30 minutes at 0° C., the reaction solution was diluted with dichloromethane (50 mL), and then washed with saturated sodium bicarbonate and saturated sodium thiosulfate. The organic phase was dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (RediSep® Flash column, 230-400 mesh, 10-30% ethyl acetate in hexane) afforded 2-bromo-4,5-difluoro-benzaldehyde (0.47 g, 39%). 1H NMR (300 MHz, CDCl3) δ 10.23 (s, 1 H), 7.77 (m, 1 H), 7.52 (m, 1 H).

1. waitAfter another 30 minutes at 0° C.
2. washwashed with saturated sodium bicarbonate and saturated sodium thiosulfate
3. dry with materialThe organic phase was dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo

ORD record

ord-f619d1858bf64d49a0ecd01de62d50fb

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08124629B2