Water → N-[4-(4-Fluorophenylcarbonyl)phenyl]-3,3,3-trifluoro-2-hydroxy-2-methyl propanamide

Participants

Reaction Steps

To a stirred, cooled (-20° C.) solution of 3,3,3-trifluoro-2-hydroxy-2-methylpropanoic acid (1.58 g, 10 mmol) in N,N-dimethylacetamide (15 mL) was added thionyl chloride (1.25 g, 10.5 mmol) and the mixture stirred at -20° to -5° C. for 1 hour. 4-Amino-4'-fluorobenzophenone (1.44 g, 6.7 mmol) was added in one portion and the reaction mixture stirred at room temperature overnight. The reaction mixture was poured into water, the cloudy solution decanted from a gum and filtered through a thin pad of Celite. The Celite was washed with methylene chloride and the solution added to a solution of the gum in methylene chloride. The combined methylene chloride solution was dried (MgSO4), filtered and the solvent removed to yield an oil. The oil was treated with 50 mL of hexane and enough methylene chloride to dissolve the oil. The solution volume was reduced slightly on a steam bath and the solution cooled and scratched until crystals formed. The volume was reduced further on the steam bath, the mixture refrigerated for several hours and the resulting solid filtered off. The 1.60 g of impure product was further purified by chromatography on 80 g of flash column silica gel using ethyl ether as eluent. The solvent was stripped from the first 150 mL of eluent, the residual oil dissolved in 15 mL of methylene chloride and added to 250 mL of rapidly stirred hexane. The resulting solid was collected and dried to yield the title propanamide (0.22 g, 58%) as a pale yellow solid; mp 131°-133° C. 1H--NMR (250 MHz, CDCl3): 1.77 (s, 3H, CH3), 4.09 (s, 1H, OH), 7.14-7.28 (m, 2H,aromatic), 7.69-7.85 (m, 6H, aromatic), 8.68 (s, 1H, NH). MS (CI, CH4): 356M+1).

Provenance & Evidence