Several analogs of the α-tropanyl esters of 2-(4-chlorophenoxy) butyric acid (SM21) and 2- phenylthiobutyric acid (SM32), endowed with potent antinociceptive and cognition enhancing activity, were synthesized, aimed at obtaining more potent and safe drug candidates. Variation of the acyl moiety (4–11), as well as the conformational restriction of atropine to give the α-tropanyl ester of 2, 3-dihydrobenzofurane-3-carboxylic acid (18), ...