STUDIES ON POTENT ANALGESICS——Ⅴ. SYNTHESIS AND ANALGESIC ACTIVITY OF THE ESTER DERIVATIVES OF N-1-(2-HYDROXY-2-PHENYLETHYL)-3-METHYL-4-PIPERIDYL-N-PHENYLPROPANA-MIDE (7302)

In this paper, thestructure and activity relationship of a series of ester derivatives of N-1-(2-hydroxy-2-phenylethyl)-3-methyl-4-piperidyl-N-phenylpropanamide(7302) is reported. It was found that after esterification of the β-hydroxy group of 7302, the analgesic activity could be maintained at a rather high level. The duration of analgesic action of some compounds could not be prolonged. In the binding test in vitro, it was found that the derivatives of esterification of 7302 decreased the affinity for receptor markedly.