Triethylamine → 4-{[2-Chloro-3-(trifluoromethyl)phenyl]carbonyl}-2-piperazinone

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Reaction Steps

2-piperazinone (1.802 g, 18 mmol, CAS [5625-67-2], commercially available e.g. from Sigma-Aldrich) and triethylamine (3.01 mL, 21.60 mmol) were dissolved in Dichloromethane (DCM) (100 ml) at 0° C. 2-Chloro-3-(trifluoromethyl)benzoyl chloride (4.81 g, 19.80 mmol, commercially available e.g. from Apollo Scientific or Shanghai FWD Chemicals) was added portionwise and the solution was stirred at room temperature for 48 hr. The solution was diluted with Dichloromethane (400 ml), was washed with 1N HCl (100 ml), water (100 ml), saturated sodium bicarbonate solution (100 ml), water (3×100 ml), and brine (100 ml), was dried over anhydrous magnesium sulfate, and was concentrated to a crude solid (5.92 g). The crude product was purified by flash chromatography (Biotage SP4, 40+M, 0% to 25% methanol/Dichloromethane as eluent) to afford crude product (5.01 g), that was recrystallised from toluene to afford pure 4-{[2-chloro-3-(trifluoromethyl)phenyl]carbonyl}-2-piperazinone (4.54 g, 14.80 mmol). LC/MS [M+H]+=307, 309, retention time=1.74 minutes (5 minute method).

Provenance & Evidence