4-cyano-3-trifluoromethyl-N-(2-hydroxy-3-phenylthio-2-trifluoromethylpropionyl)aniline → 4-cyano-3-trifluoromethyl-N-[2-(-)-camphanoyloxy-3-phenylthio-2-trifluoromethylpropionyl)aniline

Participants

Reaction Conditions

Reaction Steps

(-)-Camphanoyl chloride (4.33 g.) was added portionwise during 5 minutes to a solution of 4-cyano-3-trifluoromethyl-N-(2-hydroxy-3-phenylthio-2-trifluoromethylpropionyl)aniline (5.8 g.) in pyridine (35 ml.) and the mixture was heated at 95° C. for 150 minutes and then evaporated to dryness. Toluene (50 ml.) was added and the mixture was again evaporated to dryness. The residue was dissolved in ethyl acetate (200 ml.) and the solution was washed with water (30 ml.) and then twice with saturated aqueous sodium chloride solution (20 ml. each time), dried over magnesium sulphate and evaporated to dryness under reduced pressure. The residue was dissolved in methylene chloride (10 ml.) and the solution was flash chromatographed on silica gel (Merck 9385) using methylene chloride as eluant. There were thus obtained the two disastereoisomers of 4-cyano-3-trifluoromethyl-N-[2-(-)-camphanoyloxy-3-phenylthio-2-trifluoromethylpropionyl)aniline, the less polar isomer having m.p. 121°-123° C. and the more polar isomer having m.p. 140°-143° C.

Provenance & Evidence