Design, Synthesis, and Biological Evaluation of 1,2,3,7-Tetrahydro-6H-purin-6-one and 3,7-Dihydro-1H-purine-2,6-dione Derivatives as Corticotropin-Releasing Factor1 Receptor Antagonists

A growing body of evidence suggests that CRF1 receptor antagonism offers considerable therapeutic potential in the treatment of diseases resulting from elevated levels of CRF, such as anxiety and depression. A series of novel 1,2,3,7-tetrahydro-6H-purin-6-one and 3,7-dihydro-1H-purine-2,6-dione derivatives was synthesized and evaluated as corticotropin releasing factor-1 (CRF1) receptor antagonists. Compounds within this series, represented by compound 12d (IC50 = 5.4 nM), were found to be highly potent CRF1 receptor antagonists. In addition, compounds 12d and 12j were determined to be selective CRF1 antagonists. The synthesis, structure−activity relationships and pharmacokinetic properties of compounds within this series is presented.