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

Participants

Reaction Steps

2,3-Dibromopropionic acid, ethyl ester 7, N,N-dibenzylethylenediamine 8 and triethylamine are reacted in toluene at 80°-100° C., giving 1,4-bis(phenylmethyl)-2-piperazinecarboxylic acid, ethyl ester 9. The ester 9 is then reacted with lithium aluminum hydride in ether, under an inert atmosphere at reflux followed by treatment with an alkali base and an alkali carbonate giving 1,4-bis(phenylmethyl)-2-piperazinemethanol 10, which is then reacted with thicnyl chloride in carbon tetrachloride at 50°-60° C. followed by treatment with an alkali hydroxide, giving 2-chloromethyl-1,4-bis(phenylmethyl)piperazine 11. The compound 11 is then reacted with an amine R4, where R4 is dimethylamine, N-methylpiperazine, etc., giving a 2-substituted methyl-1,4-bis(phenylmethyl)piperazine 12 which is then catalytically reduced in ethanol and cyclohexane, giving piperazine derivative 13. Derivative 13 is then reacted with 6 in pyridine in a sealed unit under argon at 120°-130° C., giving 14. ##STR8##

Provenance & Evidence