Triethylamine → 4-(4-Methoxybenzyl)-3,3-dimethyl-piperazin-2-one

Participants

Reaction Steps

A mixture of 3,3-dimethyl-piperazin-2-one (Step 108.4) (3.7 g, 28.9 mmol), 4-methoxybenzyl bromide (5.4 mL, 37.6 mmol, 1.3 equiv) and triethylamine (5.2 mL, 37.6 mmol, 1.3 equiv) in DCM (60 mL) was stirred for 48 h at rt. Additional 5.0 mL of 4-methoxybenzyl bromide were added and the mixture was stirred for 72 h at rt, then concentrated. The residue was diluted with DCM/saturated aqueous solution of NaHCO3. The aqueous phase was separated and extracted with DCM. The organic phase was washed with H2O and brine, dried (Na2SO4), filtered and concentrated. The residue was triturated in DCM to provide 3.95 g of the title compound as a white solid: ESI-MS: 249.2 [M+H]+; TLC: Rf=0.16 (Hex/EtOAc, 2:3).

Provenance & Evidence