Hydrochloric Acid → 2-Fluoro-4-mercaptoaniline hydrochloride

Participants

Reaction Steps

2-Fluoroaniline (9.8 mL, 0.1 mol) and sodium thiocyanate (24.9 g, 0.3 mol) in MeOH (55 mL) were treated with a cold solution of bromine (5.7 mL, 0.11 mol) in saturated NaBr-MeOH solution (50 mL) added dropwise at −5-0° C. over 2 hours. After the addition, the reaction mixture was poured into cold water (200 mL) with stirring, adjusted to pH 8-9 with NaHCO3 (10 g), and stirred at 5° C. for 30 minutes. The resulting crystals were collected by filtration, washed with cold water, and dried at room temperature overnight in vacuum to give crude product 2-fluoro-4-thiocyanatoaniline (14.5 g) as slightly brown crystal. A mixture of the crude 2-fluoro-4-thiocyanatoaniline (14.5 g) and concentrated hydrochloric acid (58 mL) in EtOH (15 mL) was refluxed for 8 hours. The reaction mixture was cooled and stirred at room temperature overnight. The resulting crystals were collected by filtration, washed with cold EtOH and i-Pr2O, dried at room temperature overnight in vacuum to give the title compound as its hydrochloride salt (pale yellow crystal, 10.1 g, 56%).

Provenance & Evidence