Synthesis of a Novel Series of Tricyclic Dihydrofuran Derivatives: Discovery of 8,9-Dihydrofuro[3,2-<i>c</i>]pyrazolo[1,5-<i>a</i>]pyridines as Melatonin Receptor (MT<sub>1</sub>/MT<sub>2</sub>) Ligands
作者:Tatsuki Koike、Takafumi Takai、Yasutaka Hoashi、Masaharu Nakayama、Yohei Kosugi、Masato Nakashima、Shin-ichi Yoshikubo、Keisuke Hirai、Osamu Uchikawa
DOI:10.1021/jm200385u
日期:2011.6.23
Novel tricyclic dihydrofuran derivatives were designed, synthesized, and evaluated as melatonin receptor (MT1/MT2) ligands based on the previously reported 1,6-dihydro-2H-indeno[5,4-b]furan la. By screening the central tricyclic cores, we identified 8,9-dihydrofuro [3,2-c]pyrazolo [1,5-a]pyridine as a potent scaffold with a high ligand-lipophilicity efficiency (LLE) value. Subsequent optimization of the side chains led to identification of the potent MT1/MT2 agonist 4d (MT1, K-i = 0.062 nM; MT2, K-i = 0.420 nM) with good oral absorption and blood-brain barrier (BBB) penetration in rats. The oral administration of compound 4d exhibited a sleep-promoting action in freely moving cats at 0.1 mg/kg.