Design, synthesis and preliminary pharmacological evaluation of 1,4-diazabicyclo[4.3.0]nonan-9-ones as a new class of highly potent nootropic drugs.

Several 4-substituted 1,4-diazabicyclo[4.3.0]nonan-9-ones have been synthesized and tested in vivo on mouse passive avoidance test, to evaluate their nootropic activity. The results show that they represent a new class of nootropic drugs with a pharmacological profile very similar to that of piracetam, showing much higher potency with respect to the reference. Among the compounds studied, 7 (DM 232) shows outstanding potency, being active at the dose of 0.001 mg kg-1 sc.