Trichloroacetonitrile → Trichloroacetimidic acid (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 25.82 g (100 mmol) of (1S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol in 200 mL dry diethyl ether under nitrogen atmosphere was cooled in an ice/water bath. Neat 3 mL (20 mmol, 0.2 equiv) DBU was added to the reaction flask then the mixture was stirred at 0° C. for ten min. Slowly 15 mL (150 mmol, 1.5 equiv.) trichloroacetonitrile was added dropwise over 15 min. The reaction was stirred at 0° C. for 2 hr. during which time it became deep yellow in color. The volatiles were removed under vacuum using a cool bath (<35° C.) to give a pale brown mobile liquid which was purified by column chromatography on silica gel (3″×10″ pad) in two batches eluting with hexanes/EtOAc (9/1) then hexanes/EtOAc (4/1). The product fractions were combined and the solvent removed under vacuum to give the title compound as a pale yellow oil. 1H-NMR (CDCl3): δ: 1.74 (d, 3H, 6.5 Hz), 6.07 (q, 1H, 6.5 Hz), 7.82 (s, 1H), 7.86 (s, 2H), 8.40 (br. s, 1H) ppm.

Provenance & Evidence