Atropisomeric 4-phenyl-4H-1,2,4-triazoles as selective glycine transporter 1 inhibitors.

We report on the optimization of 4H-1,2,4-triazole derivatives to increase their activity and selectivity as glycine transporter 1 (GlyT1) inhibitors. Structure-activity relationship exploration resulted in the identification of a 3-[3-ethyl-5-(6-phenylpyridin-3-yl)-4H-1,2,4-triazol-4-yl]-2-methylbenzonitrile (14u) compound with markedly higher selectivity for GlyT1. Physiochemical studies revealed that 14u exists as a stable pair of atropisomers under physiological conditions. We successfully separated the atropisomers to obtain active enantiomer (R)-14u, which displayed favorable pharmacokinetic properties, as well as positive results in the mice Y-maze test.

Synthesis and biological evaluation of (4H-1,2,4-triazol-4-yl)isoquinoline derivatives as selective glycine transporter 1 inhibitors.

To identify novel glycine transporter 1(GlyT1) inhibitors with greater selectivity relative to GlyT2 and improved aqueous solubility, we synthesized a series of 4H-1,2,4-triazole derivatives with heteroaromatic rings at the 4-position and investigated their structure-activity relationships. Replacement of the 2-fluorophenyl group of lead compound 5 with various aromatic groups led to the identification of 5-(3-biphenyl-4-yl-5-ethyl-4H-1,2,4-triazol-4-yl)isoquinoline (15) with 38-fold selectivity between GlyT1 and GlyT2. 15 also showed improved aqueous solubility and in vivo efficacy on (+)-HA966-induced hyperlocomotion in mice over the lead compound.

Synthesis and biological evaluation of 3-biphenyl-4-yl-4-phenyl-4H-1,2,4-triazoles as novel glycine transporter 1 inhibitors.

We describe the preparation and evaluation of a novel series of glycine transporter 1 (GlyT1) inhibitors derived from a high-throughput screening hit. The SAR studies resulted in the discovery of 3-biphenyl-4-yl-4-(2-fluorophenyl)-5-isopropyl-4H-1,2,4-triazole (6p). A pharmacokinetic study was also conducted and revealed that 6p had excellent oral bioavailability and ameliorated learning impairment in passive avoidance tasks in mice.

Synthesis and evaluation of novel phenylethanolamine derivatives containing acetanilides as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential pharmacotherapies for the treatment of obesity and non-insulin dependent (type II) diabetes, we prepared a novel series of phenylethanolamine derivatives containing acetanilides and evaluated their biological activities at the human beta3-, beta2-, and beta1-ARs. Among these compounds, the 6-amino-2-pyridylacetanilide (36b), 2-amino-5-methylthiazol-4-ylacetanilide (36g), and 5-amino-1,2,4-thiadiazol-3-ylacetanilide (36h) derivatives showed potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent diabetic model.

Synthesis and structure-activity relationships of a series of substituted 2-(1H-furo[2,3-g]indazol-1-yl)ethylamine derivatives as 5-HT2C receptor agonists.

A series of novel indazole derivatives were synthesized, and their structure-activity relationships examined in order to identify potent and selective 5-HT2C receptor agonists. Among these compounds, (S)-2-(7-ethyl-1H-furo[2,3-g]indazol-1-yl)-1-methylethylamine (YM348) had a good in vitro profile, that is, high agonistic activity to the human 5-HT2C receptor subtype (EC50 = 1.0 nM) and high selectivity over 5-HT2A receptors. This compound was also effective in a rat penile erection model when administered p.o.