Triethylamine → Ethyl 1,4-dibenzylpiperazine-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a hot (about 80° C.) solution of N,N′-dibenzylethylenediamine (216 g, 0.9 mol) and triethylamine (300 uL, 2.16 mol) in toluene (650 mL) was added rapidly dropwise ethyl 2,3-dibromopropionate (240 g, 0.93 mol) in toluene (650 mL). After the addition, the reaction mixture was stirred at 80° C. for about three hours. A temperature below about 95° C. was maintained. The heavy precipitate was filtered off and then solvent and excess TEA removed. t-butyl methyl ether (about 300 mL) was added. The reaction was stirred well, and any precipitate that was formed was filtered. The reaction was concentrated to a pale yellow oil (about 287 g, about 94%)

Provenance & Evidence