Dimethylformamide → 3-Bromo-4-fluorobenzoyl chloride

A solution of 3-bromo-4-fluorobenzoic acid (976 mg, 4.46 mmol) in DCM (25 mL) was stirred at rt and treated with oxalyl chloride (1.950 mL, 22.28 mmol), followed by a drop of DMF, causing gas evolution to commence. After 2.5 h, the solution was heated to boiling for 1-2 min and allowed to cool to rt. After 3 h total, the solution was concentrated to provide 3-bromo-4-fluorobenzoyl chloride as a white solid (1.00 g, 94%). A portion of this material (200 mg, 0.842 mmol) was added to an ice-cold solution of 4-fluoroaniline (0.081 mL, 0.842 mmol) in pyridine (4 mL), and the solution was stirred at rt for 65 h The solution was concentrated and the residue was stirred in 1 M hydrochloric acid, forming a precipitate which was collected by filtration, washed with water and dried to provide 3-bromo-4-fluoro-N-(4-fluorophenyl)benzamide as an off-white solid (227.5 mg, 80%). 1H NMR (400 MHz, DMSO-d6) δ 10.38 (s, 1H) 8.29 (dd, J=6.7, 2.1 Hz, 1H) 8.01 (ddd, J=8.6, 4.8, 2.2 Hz, 1H) 7.75 (dd, J=9.0, 5.1 Hz, 2H) 7.55 (t, J=8.6 Hz, 1H) 7.20 (t, J=8.9 Hz, 2H). Mass spectrum m/z 312, 314 (M+H)+.

1. temperaturethe solution was heated
2. waitto boiling for 1-2 min
3. waitAfter 3 h total
4. concentrationthe solution was concentrated

ORD record

ord-d11c41cfe6db4f0a9a182dc40b60bb10

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08084620B2