Discovery of benzo[d]imidazo[5,1-b]thiazole as a new class of phosphodiesterase 10A inhibitors.

The design, synthesis and structure activity relationship studies of a series of compounds from benzo[d]imidazo[5,1-b]thiazole scaffold as phosphodiesterase 10A (PDE10A) inhibitors are discussed. Several potent analogs with heteroaromatic substitutions (9a-d) were identified. The anticipated binding mode of these analogs was confirmed by performing the in silico docking experiments.

Imidazopyridazinones as novel PDE7 inhibitors: SAR and in vivo studies in Parkinson's disease model.

The synthesis and structure-activity relationship studies of a series of compounds from imidazopyridazinone scaffold as PDE7 inhibitors are disclosed. Potent analogs such as compounds 7 (31nM), 8 (27nM), and 9 (12nM) were identified. The PDE selectivity and pharmacokinetic profile of compounds 7, 8 and 9 are also disclosed.

Isothiazole and isoxazole fused pyrimidones as PDE7 inhibitors: SAR and pharmacokinetic evaluation.

The synthesis and structure-activity relationship studies of isothiazole and isoxazole fused pyrimidones as PDE7 inhibitors are discussed. The pharmacokinetic profile of 10 and 21 with adequate CNS penetration, required for in vivo Parkinson's disease models, are disclosed.