Hydrochloric Acid → 2-Amino-1-[4-fluoro-3-(trifluoromethyl)phenyl]ethanone Hydrochloride

Participants

Reaction Steps

To a solution of 2-bromo-1-(4-fluoro-3-(trifluoromethyl)phenyl)ethanone (60.00 g 1.00 equiv; 210.50 mmoles (mmol)) in ethylacetate (EA) (450 mL; 4.60 moles (mol)), add 1,3,5,7-tetraazatricyclo-[3.3.1.13,7]decane (Methenamine, 1.10 equiv; 231.55 mmol; 32.46 g) and stir at RT overnight. Remove the solvent in vacuo and triturate the solid with methyl-t-butylether (MTBE), filter and dry in vacuo. Add ethanol (450 mL; 7.73 mol) followed by hydrogen chloride (36.5 wt/wt % in water) (150 mL; 8.30 equiv; 1.75 mol) and stir the mixture overnight. Remove the solvent in vacuo and dry the solid in vacuo at 50° C. for 1 week to give the title compound (54.23 g; 100% yield) as a white solid with some amount of ammonium salt. 1H NMR (300 MHz, DMSO): 8.69-8.59 (m, 4H), 8.07-8.01 (m, 1H), 4.95 (d, J=5.2 Hz, 2H). Use the solid as is.

Provenance & Evidence