4-Fluorobenzonitrile → 4-Fluoro-n-hydroxybenzimidamide

Participants

Reaction Steps

To a stirred solution of 4-fluorobenzonitrile (10 g, 82.5 mmol) in EtOH (71 mL) was added NH2OH.HCl (6.42 g, 92.1 mmol), followed by NaOH pellets (3.69 g, 92.1 mmol). The resulting reaction mixture was then heated at reflux for 3 h. The reaction progress was monitored by TLC using solvent system EtOAc:Hexane (1:1). After completion of reaction the solvent was evaporated under reduced pressure and the minimum amount of water (ca. 30 mL) was added to the residue. The mixture was extracted with dichloromethane (3×300 mL), dried over Na2SO4, and concentrated under vacuum. The crude compound obtained was recrystallized from hot toluene to obtain 8.0 g (63%) of 4-fluoro-N′-hydroxybenzimidamide as a colorless solid. 1H NMR (400 MHz, DMSO-d6): δ 9.6 (s, 1H), 7.07-7.67 (m, 2H), 7.18 (t, 2H, J=8.8 Hz), 5.80 (br s, 2H); LC-MS m/z calculated for [M+H]+ 155.05. found 155.1.

Provenance & Evidence