Pharmacophoric comparison between papaverine and tofisopam led to identify three new series of micro-to sub-micromolar inhibitors of phosphodiesterase-4, including 7, 8-dialkoxy- 2, 3-benzodiazepin-4-one derivatives, 7, 8-dialkoxy-1, 4-benzodiazepin-2-one derivatives, and dialkoxybenzophenone derivatives.