Thionyl Chloride → 3,3,3-trifluoro-N-(4-flurosulfonylphenyl)-2-hydroxy-2-methylpropanamide

Participants

Reaction Conditions

Reaction Steps

To a cooled (-20° C.) solution of α-trifluoromethyl lactic acid (2.0 g) in dry N,N-dimethylacetamide (15 ml) was added thionyl chloride (0.97 mL) dropwise over 10 minutes. The reaction mixture was stirred at -20° C. for 1 hour, warmed to 0° C. over 1 hour, then treated with sulfanilyl fluoride (2.22 g) in one portion and heated at 100° C. for 24 hours. After cooling to 22° C. the reaction mixture was diluted with water (150 ml) and extracted with ethyl acetate (3×35 ml). The combined organic extracts were washed with water, brine, dried and the solvent removed under reduced pressure. The crude product was purified by chromatography (13:1 CH2Cl2 :Et2 0) and recrystallised from methyl-t-butyl ether to give 3,3,3-trifluoro-N-[4-(fluorosulfonyl)phenyl]-2-hydroxy-2-methylpropanamide as colourless crystals, (1.7 g); mp 152°-154° C.; MS: m/z=316(M+1); NMR (CDCl3): 1.78 (s,3), 3.51 (broad s), 7.86-7.89 (m, 2), 7.99-8.03 (m,2), 8.79 (broad s,1). Analysis for C10H9 F4NO4S: Calculated: C, 38.10; H,2.88; N, 4.44; Found: C, 38.21; H, 2.97; N, 4.44.

Provenance & Evidence