N-(Piperazinoacyl) and N-(piperazinoalkyl) derivatives of 4-cyclopentylaniline and related compounds: synthesis and pharmacological screening
Five N-(4-cydopentylphenyl)haloalkanecarboxamides were reacted with I-methylpiperazine and 1-(2-hydroxyethyl)piperazine to give the corresponding N-(4-cydopentylphenyl)piperazinoalkanecarboxamides IabVab. Their reduction with lithium aluminium hydride afforded the triamines VIIab-XIab. Acylation of the N-(4-methylpiperazino)alkyl-4-cydopentylanilines 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-cydopentylanilines VIIb and IXbXIb 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.