Synthesis and analgesic activity of new compounds combining azaadamantane and monoterpene moieties

Synthesis of new compounds that combine the diazaadamantane and monoterpenoid moieties was carried out based on the reaction between dimethylbispidinone and monoterpene-derived aldehydes. Investigation of the analgesic activity of the obtained products revealed that compound 5a synthesized from (−)-myrtenal had a higher efficacy compared with the reference drug, diclofenac sodium, in the acetic acid-induced writhing and hot plate tests. Compound 5a exhibits a low acute toxicity and does not cause damage to the gastric mucosa, and its analgesic effect is, at least partially, mediated by the cannabinoid system involving CB1 receptors.