To a stirred, cooled (-20° C.) solution of 3,3,3-trifluoro-2-hydroxy-2-methylpropanoic acid (0.71 g, 4.5 mmol) in N,N-dimethylacetamide (10 mL) was added thionyl chloride (0.54 g, 4.5 mmol) and the mixture stirred at -10° to -15° C. for 1 hour. 3-Fluoro-4-(phenyl sulfonyl)benzeneamine (0.75 g, 3.0 mmol) was added in one portion and the reaction mixture stirred at room temperature overnight. The mixture was poured into water and the aqueous solution filtered through Celite. The Celite was washed with methylene chloride (75 mL), the organic extract dried (MgSO4) and concentrated in vacuo to a tan solid. Purification by flash column chromatography (5% v/v ethyl acetate/methylene chloride) yielded the title propanamide as a white solid (0.79 g, 68%); mp 147°-149° C. 1H-NMR (250 MHz, d6-DMSO): 1.58 (s, 3H, CH3) 7.65-7.69 (m, 4H, aromatic +OH) 7.74 (d, 1H, J=7.2 Hz, aromatic) 7.83-7.94 (m, 3H, aromatic) 8.02 (t, 1H, J=8.3 Hz, aromatic) 10.61 (s, 1H, NH). MS (CI, CH4): 392 (M+1). Analysis for C16H13F4NO4S: Calculated: C, 49.12; H, 3.35; N, 3.58. Found: C, 48.91; H, 3.28; N, 3.53.
