N-(piperazinoacyl) and N-(piperazinoalkyl) derivatives of 4-cyclopentylaniline and related compounds: Synthesis and pharmacological screening

Abstract

Five N-(4-cyclopentylphenyl)haloalkanecarboxamides were reacted with 1-methylpiperazine and 1-(2-hydroxyethyl)piperazine to give the corresponding N-(4-cyclopentylphenyl)piperazinoalkanecarboxamides Iab -Vab. Their reduction with lithium aluminium hydride afforded the triamines VIIab - XIab. Acylation of the N-(4-methylpiperazino)alkyl-4-cyclopentylanilines Xa and XIa with propionyl chloride resulted in the propionanilides XIVa and XVa, whereas a similar reaction of the N-(4-(2-hydroxyethyl)piperazino)alkyl-4-cyclopentylanilines VIIb and IXb - XIb produced the propionoxypropionanilides XIIc - XVc. Ethanolysis of these compounds afforded corresponding hydroxypropionanilides XIIb - XVb. Many of the basic amides showed local anaesthetic and papaverine-like antispasmodic activity. The propionanilides XIIb, XIVc, and XVa proved interesting analgesic effects in the peritoneal test in mice.