Optimization of 5-Pyridazin-3-one Phenoxypropylamines as Potent, Selective Histamine H3 Receptor Antagonists with Potent Cognition Enhancing Activity
摘要:
Previous studies have shown that (5-{4-[3-(R)-2-methylpyrrolin-1-yl-propoxy]phenyl}-2H-pyridazin-3-one) 2 had high affinity for both the human (hH(3)R K-i = 2.8 nM) and rat H(3)Rs (rH(3)R K-i = 8.5 nM) but displayed low oral bioavailability in the rat. Optimization of the 5-pyridazin-3-one R-2 and R-6 positions to improve the pharmacokinetic properties over 2 led to the identification of 5-{4-[3-(R)-2-methylpyrrolidin-1-yl)propoxy]phenyl}-2-pyridin-2-yl-2H-pyridazin-3-one 29. Compound 29 displayed high affinity for both human and rat H(3)Rs (hH3R K-i = 1.7 nM, rH(3)R K = 3.7 nM) with a greater than 1000-fold selectivity over the other histamine receptor subtypes and favorable pharmacokinetic properties across species (F = 78% rat, 92% dog, 96% monkey). It showed low binding to human plasma proteins, weakly inhibited cytochrome P450 isoforms, and displayed an excellent safety profile for a CNS-active compound. 29 displayed potent H3R antagonist activity in the brain in a rat dipsogenia model and demonstrated enhancement of cognitive function in a rat social recognition model at low doses. However, the development of compound 29 was discontinued because of genotoxicity.
Optimization of 5-Pyridazin-3-one Phenoxypropylamines as Potent, Selective Histamine H3 Receptor Antagonists with Potent Cognition Enhancing Activity
摘要:
Previous studies have shown that (5-{4-[3-(R)-2-methylpyrrolin-1-yl-propoxy]phenyl}-2H-pyridazin-3-one) 2 had high affinity for both the human (hH(3)R K-i = 2.8 nM) and rat H(3)Rs (rH(3)R K-i = 8.5 nM) but displayed low oral bioavailability in the rat. Optimization of the 5-pyridazin-3-one R-2 and R-6 positions to improve the pharmacokinetic properties over 2 led to the identification of 5-{4-[3-(R)-2-methylpyrrolidin-1-yl)propoxy]phenyl}-2-pyridin-2-yl-2H-pyridazin-3-one 29. Compound 29 displayed high affinity for both human and rat H(3)Rs (hH3R K-i = 1.7 nM, rH(3)R K = 3.7 nM) with a greater than 1000-fold selectivity over the other histamine receptor subtypes and favorable pharmacokinetic properties across species (F = 78% rat, 92% dog, 96% monkey). It showed low binding to human plasma proteins, weakly inhibited cytochrome P450 isoforms, and displayed an excellent safety profile for a CNS-active compound. 29 displayed potent H3R antagonist activity in the brain in a rat dipsogenia model and demonstrated enhancement of cognitive function in a rat social recognition model at low doses. However, the development of compound 29 was discontinued because of genotoxicity.
Synthesis and structure–activity relationship of 5-pyridazin-3-one phenoxypiperidines as potent, selective histamine H3 receptor inverse agonists
作者:Ming Tao、Lisa D. Aimone、John A. Gruner、Joanne R. Mathiasen、Zeqi Huang、Jacquelyn Lyons、Rita Raddatz、Robert L. Hudkins
DOI:10.1016/j.bmcl.2011.11.118
日期:2012.1
Optimization of the R2 and R6 positions of (5-4-[3-(R)-2-methylpyrrolin-1-yl-propoxy]phenyl}-2H-pyridazin-3-one) 2a with constrained phenoxypiperidines led to the identification of 5-[4-(cyclobutyl-piperidin-4-yloxy)-phenyl]-6-methyl-2H-pyridazin-3-one 8b as a potent, selectivehistamineH3receptor antagonist with favorable pharmacokinetic properties. Compound 8b had an excellent safety genotoxocity