Design, synthesis and preliminary pharmacological evaluation of new piperidine and piperazine derivatives as cognition-enhancers

A series of 2-oxopiperazine, 4-aminomethyl-, 3-amino- and 3-aminomethylpiperidine analogues of DM235 (sunifiram) and MN19 (sapunifiram), two previously reported potent cognition-enhancers, have been synthesized and tested in the mouse passive-avoidance test. The compounds display minimal effective doses in the range 0.3–10 mg/kg. Although the new substances do not show improved activity when compared to the parent compounds, some useful information has been obtained to understand structure–activity relationships. In addition, the 3- aminopiperidine moiety appears to be a promising scaffold to synthesize new drugs endowed with cognition-enhancing activity.