Triethylamine → 4-[(3-Chloro-2-methylphenyl)carbonyl]-2-piperazinone

Participants

Reaction Steps

2-Oxopiperazine (1.5 g, 14.98 mmol, commercially available from e.g. Sigma-Aldrich) was suspended in dry dichloromethane (DCM) (40 mL), cooled in an ice bath before adding triethylamine (3.13 mL, 22.47 mmol), followed by 3-chloro-2-methylbenzoyl chloride (I130) (2.97 g, 15.73 mmol) in Dichloromethane (DCM) (15 mL) dropwise over 15 mins. The reaction mixture was then stirred for 16 hours at RT, under argon. Solvent removed under reduced pressure. Residue partitioned between DCM (100 ml) and water (60 ml). Layers separated and aqueous layer extracted with DCM (2×50 ml). Combined extracts were washed with saturated sodium bicarbonate solution (70 ml), brine (70 ml), dried (Na2SO4), filtered and evaporated to afford an off-white solid. Solid was stirred in n-hexane (50 mL) at 55° C. for 30 mins, before filtering and drying in the vacuum oven at 40° C. for 18 hours to afford the desired product in 3.39 g as a pale yellow solid.

Provenance & Evidence