抄録
N-(2-Piperazinoethyl) propionanilides were synthesized by the reduction of piperazino-acetanilide or the condensation of N-(β-bromoethyl) aniline hydrobromide and piperazines. Comparing the two methods, the condensation method is superior from the point of yield and easiness. The analgesic activity test showed that (A) N-[1-methyl-2-(4-methylpiperazino) ethyl] propionanilide (7a) possessed ca. 1/9 of the analgesic effect of morphine, and N-[2-(4-phenethylpiperazino) ethyl] propionanilide (7e) and N-[2-(3-methyl-4-phenethylpiperazino) ethyl] propionanilide (7i) possessed ca. 1/2 of the analgesic effect of pentazocine ; (B) the compound (7a), (7e), (7i) showed strong acute toxicities ; (C) methyl group at the 3-position of piperazine ring decreased analgesic activity ; (D) phenyl group at the 3-position of piperazine ring deactivated the analgesics.
