Triethylamine → 3-(4-Trifluoromethylbenzoyl)piperidine-2,4-dione

Participants

Reaction Steps

Dry triethylamine (3.24 g) was added at 0°-5° C. to a stirred solution of diethyl cyanophosphate (1.96 g), 4-trifluoromethylbenzoic acid (2.28 g) and piperidine-2,4-dione (1.13 g) in dry dimethylformamide (50 ml) and the mixture stirred at ambient temperature for 5 hours. The mixture was diluted with dichloromethane (70 ml) and the solution washed successively with 2N hydrochloric acid (70 ml) and water (5×30 ml). The dichloromethane solution was dried over magnesium sulphate and evaporated under reduced pressure to give a brown solid which was recrystallised from toluene (11 ml) to give 3-(4-trifluoromethylbenzoyl)piperidine-2,4-dione (0.44 g), mp 197°-200° C., as a pale green crystalline solid.

Provenance & Evidence