Discovery of a Series of Substituted 1-((1,2,3-Triazol-4-yl)methoxy)pyrimidines as Brain Penetrants and Potent GluN2B-Selective Negative Allosteric Modulators.

Herein, we describe a series of substituted 1-((1,2,3-triazol-4-yl)methoxy)pyrimidines as potent GluN2B negative allosteric modulators. Exploration of several five- and six-membered heterocycles led to the identification of O-linked pyrimidine analogues that possessed a balance of potency and desirable ADME profiles. Due to initial observations of metabolic saturation, early metabolite identification studies were conducted on compound and the results drove further iterative optimization efforts to avoid the formation of undesired saturating metabolites.

Discovery and SAR studies of 2-alkyl-3-phenyl-2,4,5,6,7,8-hexahydropyrazolo[3,4-d]azepines as 5-HT inhibitors leading to the identification of a clinical candidate.

We report here the synthesis and characterization of a dual 5-HT / 5-HT receptor antagonist 3-(4-Fluoro-phenyl)-2-isopropyl-2,4,5,6,7,8-hexahydro-1,2,6-triaza-azulene (4j). 4j is a high affinity 5-HT and 5-HT receptor ligand having a pK = 8.1 at both receptors.

Substituted Azabicyclo[2.2.1]heptanes as Selective Orexin-1 Antagonists: Discovery of JNJ-54717793.

The orexin system consists of two neuropeptides (orexin-A and orexin-B) that exert their mode of action on two receptors (orexin-1 and orexin-2). While the role of the orexin-2 receptor is established as an important modulator of sleep wake states, the role of the orexin-1 receptor is believed to play a role in addiction, panic, or anxiety. In this manuscript, we describe the optimization of a nonselective substituted azabicyclo[2.

A Dipolar Cycloaddition Reaction To Access 6-Methyl-4,5,6,7-tetrahydro-1H-[1,2,3]triazolo[4,5-c]pyridines Enables the Discovery Synthesis and Preclinical Profiling of a P2X7 Antagonist Clinical Candidate.

A single pot dipolar cycloaddition reaction/Cope elimination sequence was developed to access novel 1,4,6,7-tetrahydro-5H-[1,2,3]triazolo[4,5-c]pyridine P2X7 antagonists that contain a synthetically challenging chiral center. The structure-activity relationships of the new compounds are described. Two of these compounds, (S)-(2-fluoro-3-(trifluoromethyl)phenyl)(1-(5-fluoropyrimidin-2-yl)-6-methyl-1,4,6,7-tetrahydro-5H-[1,2,3]triazolo[4,5-c]pyridin-5-yl)methanone (compound 29) and (S)-(3-fluoro-2-(trifluoromethyl)pyridin-4-yl)(1-(5-fluoropyrimidin-2-yl)-6-methyl-1,4,6,7-tetrahydro-5H-[1,2,3]triazolo[4,5-c]pyridin-5-yl)methanone (compound 35), were found to have robust P2X7 receptor occupancy at low doses in rat with ED values of 0.

4-Methyl-6,7-dihydro-4H-triazolo[4,5-c]pyridine-Based P2X7 Receptor Antagonists: Optimization of Pharmacokinetic Properties Leading to the Identification of a Clinical Candidate.

The synthesis and preclinical characterization of novel 4-(R)-methyl-6,7-dihydro-4H-triazolo[4,5-c]pyridines that are potent and selective brain penetrant P2X7 antagonists are described. Optimization efforts based on previously disclosed unsubstituted 6,7-dihydro-4H-triazolo[4,5-c]pyridines, methyl substituted 5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazines, and several other series lead to the identification of a series of 4-(R)-methyl-6,7-dihydro-4H-triazolo[4,5-c]pyridines that are selective P2X7 antagonists with potency at the rodent and human P2X7 ion channels. These novel P2X7 antagonists have suitable physicochemical properties, and several analogs have an excellent pharmacokinetic profile, good partitioning into the CNS and show robust in vivo target engagement after oral dosing.

Polypharmacology of Small-Molecule Modulators of the 5-Lipoxygenase Activating Protein (FLAP) Observed via a High-throughput Lipidomics Platform.

Leukotrienes (LTs) and related species are proinflammatory lipid mediators derived from arachidonic acid (AA) that have pathological roles in autoimmune and inflammatory conditions, cardiovascular diseases, and cancer. 5-Lipoxygenase activating protein (FLAP) plays a critical accessory role in the conversion of AA to LTA4, and its subsequent conversion to LTC4 by LTC4 synthase. Pharmacological inhibition of FLAP results in a loss of LT production by preventing the biosynthesis of both LTB4 and LTC4, making it an attractive target for the treatment of inflammatory diseases in which LTs likely play a role.

Identification and SAR of Glycine Benzamides as Potent Agonists for the GPR139 Receptor.

A focused high throughput screening for GPR139 was completed for a select 100K compounds, and new agonist leads were identified. Subsequent analysis and structure-activity relationship studies identified (S)-3-chloro-N-(2-oxo-2-((1-phenylethyl)amino)ethyl)benzamide 7c as a potent and selective agonist of hGPR139 with an EC50 = 16 nM. The compound was found to cross the blood-brain barrier and have good drug-like properties amenable for oral dosing in rat.

Identification of Hydroxybenzoic Acids as Selective Lactate Receptor (GPR81) Agonists with Antilipolytic Effects.

Following the characterization of the lactate receptor (GPR81), a focused screening effort afforded 3-hydroxybenzoic acid 1 as a weak agonist of both GPR81 and GPR109a (niacin receptor). An examination of structurally similar arylhydroxy acids led to the identification of 3-chloro-5-hydroxybenzoic acid 2, a selective GPR81 agonist that exhibited favorable in vivo effects on lipolysis in a mouse model of obesity.

The discovery and synthesis of JNJ 31020028, a small molecule antagonist of the Neuropeptide Y Y₂ receptor.

A series of small molecules based on a chemotype identified from our compound collection were synthesized and tested for binding affinity (IC(50)) at the human Neuropeptide Y Y(2) receptor (NPY Y(2)). Six of the 23 analogs tested possessed an NPY Y(2) IC(50) ≤ 15 nM. One member of this series, JNJ 31020028, is a selective, high affinity, receptor antagonist existing as a racemic mixture.

Novel tetrahydropyrido[3,2-c]pyrroles as 5-HT(7) antagonists.

The synthesis and SAR for a novel series of tetrahydropyrido[3,2-c]pyrroles is described. Optimization of the pendant aryl ring lead to high binding affinity at the 5-HT(7) receptor when small lipophilic groups were placed in the para position. Modification of the N-benzyl group and secondary amine were not well tolerated.

Diamine-based human histamine H3 receptor antagonists: (4-aminobutyn-1-yl)benzylamines.

A series of (4-aminobutyn-1-yl)benzylamines were prepared and the SAR around three key areas: (1) the amine attached to the butynyl linker (R(3)R(4)N-); (2) the benzylamine moiety (R(1)R(2)N-); and (3) the point of attachment of the benzylamine group (R(1)R(2)N- in the ortho, meta, or para positions) was examined. One compound, 4-[3-(4-piperidin-1-yl-but-1-ynyl)-benzyl]-morpholine (9s) was chosen for further profiling and found to be a selective histamine H(3) antagonist with desirable drug-like properties. Ex vivo receptor occupancy studies established that 9s does occupy H(3) binding sites in the brain of rats after oral administration.

Blockade of orexin-1 receptors attenuates orexin-2 receptor antagonism-induced sleep promotion in the rat.

Orexins are peptides produced by lateral hypothalamic neurons that exert a prominent role in the maintenance of wakefulness by activating orexin-1 (OX1R) and orexin-2 (OX2R) receptor located in wake-active structures. Pharmacological blockade of both receptors by the dual OX1/2R antagonist (2R)-2-[(1S)-6,7-dimethoxy-1-{2-[4-(trifluoromethyl)phenyl]ethyl}-3,4-dihydroisoquinolin-2(1H)-yl]-N-methyl-2-phenylethanamide (almorexant) has been shown to promote sleep in animals and humans during their active period. However, the selective distribution of OX1R and OX2R in distinct neuronal circuits may result in a differential impact of these receptors in sleep-wake modulation.

Novel imidazole-based histamine H3 antagonists.

A novel series of imidazole containing histamine H(3) receptor ligands were investigated and found to be potent functional antagonists. After improving the stability of these molecules towards liver microsomes, these compounds were found to have no appreciable affinity for CYP P450s. Subsequent in vivo experiments showed significant brain uptake of (4-chloro-phenyl)-[2-(1-isopropyl-piperidin-4-ylmethoxy)-3-methyl-3H-imidazol-4-yl]-methanone 22.

2-Alkyl-4-aryl-pyrimidine fused heterocycles as selective 5-HT2A antagonists.

The synthesis and SAR for a novel series of 2-alkyl-4-aryl-tetrahydro-pyrido-pyrimidines and 2-alkyl-4-aryl-tetrahydro-pyrimido-azepines is described. Representative compounds were shown to be subtype selective 5-HT(2A) antagonists. Optimal placement of a basic nitrogen relative to the pyrimidine and the presence of a 4-fluorophenyl group in the pyrimidine 4-position was found to have a profound effect on affinity and selectivity.

Palladium-catalyzed coupling of pyrazole triflates with arylboronic acids.

[reaction: see text] A general protocol for the palladium-mediated Suzuki coupling reaction of pyrazole triflates and aryl boronic acids has been developed. The use of additional dppf ligand was determined to increase product yields allowing for the use of a broad range of reaction substrates.

4-phenoxypiperidines: potent, conformationally restricted, non-imidazole histamine H3 antagonists.

Two new series of 4-(1-alkyl-piperidin-4-yloxy)-benzonitriles and 4-(1-isopropyl-piperidin-4-yloxy)-benzylamines have been prepared. In vitro activity was determined at the recombinant human H(3) receptor and several members of these new series were found to be potent H(3) antagonists. The present compounds contain a 4-phenoxypiperidine core, which behaves as a conformationally restricted version of the 3-amino-1-propanol moiety common to the many previously described non-imidazole histamine H(3) ligands.

Novel substituted 4-phenyl-[1,3]dioxanes: potent and selective orexin receptor 2 (OX(2)R) antagonists.

Orexins, also termed hypocretins, consist of two neuropeptide agonists (orexin A and B) interacting with two known G-protein coupled receptors (OX(1)R and OX(2)R). In addition to other biological functions, the orexin-2 receptor is thought to be an important modulator of sleep and wakefulness. Herein we describe a series of novel, selective OX(2)R antagonists consisting of substituted 4-phenyl-[1,3]dioxanes.

The first potent and selective non-imidazole human histamine H4 receptor antagonists.

Following the discovery of the human histamine H4 receptor, a high throughput screen of our corporate compound collection identified compound 6 as a potential lead. Investigation of the SAR resulted in the discovery of novel compounds 10e and 10l, which are the first potent and selective histamine H4 receptor antagonists to be described.

A new class of diamine-based human histamine H3 receptor antagonists: 4-(aminoalkoxy)benzylamines.

4-(Aminoalkoxy)benzylamines were prepared and screened for in vitro activity at the human histamine H(3) receptor. Some members of this series exhibited subnanomolar binding affinities. Analogues in which one nitrogen atom was replaced with a methine group showed greatly reduced binding affinities.