Triethylamine → HCID 66598990, Verbindung

2-piperazinone (0.5 g, 4.99 mmol, commercially available from e.g. Sigma-Aldrich) was dissolved in dichloromethane (DCM) (30 mL), and to this was added triethylamine (0.835 mL, 5.99 mmol). The solution was then cooled to 0° C. before 4-chloro-2-(trifluoromethyl)benzoyl chloride (1.335 g, 5.49 mmol, commercially available from e.g. 3B Scientific or APAC) in dichloromethane (DCM) (5 mL) was added dropwise. The solution was stirred, under argon, for 30 minutes before the solvent was evaporated in vacuo. The remaining residue was then dissolved in DCM (20 mL) and the solution was washed with water (10 mL), a saturated solution of sodium bicarbonate (10 mL) and brine (10 mL). The organic phase was then dried over anhydrous sodium sulphate, and the solid sodium sulphate was then filtered off. The solvent was then evaporated in vacuo, and the remaining solid was stirred in hexane, at 55° C., for 30 minutes. The solid was then filtered off to yield the desired product in 1.445 g.