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.

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.

Gram-Scale Synthesis of a β-Secretase 1 (BACE 1) Inhibitor.

Development of a scalable synthesis of an oxazine class of β-secretase inhibitor is described. Trifluoromethylated acyloin synthesis by the reaction of a mandelic acid with trifluoroacetic anhydride in the presence of pyridine (Dakin-West reaction) was used as an efficient strategy to install the key trifluoromethyl substituent on the oxazine ring. Diastereoselective addition of methyl magnesium bromide to a cyclic sulfamidate imine and trimethylsilyl trifluoromethanesulfonate catalyzed intramolecular amidine formation to yield oxazine-3-amine are some of the significant, novel synthetic methods developed in this synthesis.

Allyl-Assisted, Cu(I)-Catalyzed Azide-Alkyne Cycloaddition/Allylation Reaction: Assembly of the [1,2,3]Triazolo-4,5,6,7-tetrahydropyridine Core Structure.

We report a Cu(I)-catalyzed azide-alkyne-allyl halide three-component reaction for a one-pot synthesis of 1,4-disubstituted 5-allyl-1,2,3-triazoles. The allyl moiety provides not only the electrophile but also a coordinating ligand to Cu, which is essential for the reaction to occur under mild conditions. A concise synthesis of a potential drug candidate 1 is realized based on this key reaction.

Discovery of a novel series of selective HCN1 blockers.

The discovery of a series of novel, potent, and selective blockers of the cyclic nucleotide-modulated channel HCN1 is disclosed. Here we report an SAR study around a series of selective blockers of the HCN1 channel. Utilization of a high-throughput VIPR assay led to the identification of a novel series of 2,2-disubstituted indane derivatives, which had moderate selectivity and potency at HCN1.

JNJ-26070109 [(R)4-bromo-N-[1-(2,4-difluoro-phenyl)-ethyl]-2-(quinoxaline-5-sulfonylamino)-benzamide]: a novel, potent, and selective cholecystokinin 2 receptor antagonist with good oral bioavailability.

JNJ-26070109 [(R)4-bromo-N-[1-(2,4-difluoro-phenyl)-ethyl]-2-(quinoxaline-5-sulfonylamino)-benzamide] is a representative of a new chemical class of competitive antagonists of cholecystokinin 2 (CCK2) receptors. In this study, the primary in vitro pharmacology of JNJ-26070109 was evaluated along with the pharmacokinetic and pharmacodynamic properties of this compound in rat and canine models of gastric acid secretion. JNJ-26070109 expressed high affinity for human (pK(I) = 8.

1,2-diamino-ethane-substituted-6,7,8,9-tetrahydro-5H-pyrimido[4,5-d]azepines as TRPV1 antagonists with improved properties.

Based upon a previously reported lead compound 1, a series of 1,2-diamino-ethane-substituted-6,7,8,9-tetrahydro-5H-pyrimido[4,5-d]azepines were synthesized and evaluated for improved physiochemical and pharmacokinetic properties while maintaining TRPV1 antagonist activity. Structure-activity relationship studies directed toward improving the aqueous solubility (pH 2 and fasted-state simulated intestinal fluid (SIF)) and rat pharmacokinetics led to the discovery of compound 13. Aqueous solubility of compound 13 (pH 2 ≥237 μg/mL and SIF=11 μg/mL) was significantly improved over compound 1 (pH 2=5 μg/mL and SIF=0.

Indole- and benzothiophene-based histamine H3 antagonists.

Previous research on histamine H(3) antagonists has led to the development of a pharmacophore model consisting of a central phenyl core flanked by two alkylamine groups. Recent investigation of the replacement of the central phenyl core with heteroaromatic fragments resulted in the preparation of novel 3,5-, 3,6- and 3,7-substituted indole and 3,5-substituted benzothiophene analogs that demonstrate good to excellent hH(3) affinities. Select analogs were profiled in a rat pharmacokinetic model.

Anthranilic sulfonamide CCK1/CCK2 dual receptor antagonists I: discovery of CCKR1 selectivity in a previously CCKR2-selective lead series.

A series of CCK2R-selective anthranilic amides is shown to derive CCK1R affinity via selective substitution of the amide side chain. Thus, extending the length of the original benzamide side chain by a single methylene unit imparts CCK1R affinity to the series, and further fine tuning of the affinity results in CCK1R selectivity of greater than 100-fold.

Discovery of potent cholecystokinin-2 receptor antagonists: elucidation of key pharmacophore elements by X-ray crystallographic and NMR conformational analysis.

A novel series of cholecystokinin-2 receptor (CCK-2R) antagonists has been identified, as exemplified by anthranilic sulfonamide 1 (pK(i)=7.6). Pharmacokinetic and stability studies indicated that this series of compounds suffered from metabolic degradation, and that both the benzothiadiazole and piperidine rings were rapidly oxidized by liver enzymes.

Synthesis and solid-phase purification of anthranilic sulfonamides as CCK-2 ligands.

A novel strategy for the synthesis of cholecystokinin-2 receptor ligands was developed. The route employs a solution-phase synthesis of a series of anthranilic sulfonamides followed by a resin capture purification strategy to produce multi-milligram quantities of compounds for bioassay. The synthesis was used to produce >100 compounds containing various functional groups, highlighting the general applicability of this strategy and to address specific metabolism issues in our CCK-2 program.

Tetrahydroindazole inhibitors of bacterial type II topoisomerases. Part 2: SAR development and potency against multidrug-resistant strains.

We have previously reported a novel class of tetrahydroindazoles that display potency against a variety of Gram-positive and Gram-negative bacteria, potentially via interaction with type II bacterial topoisomerases. Herein are reported SAR investigations of this new series. Several compounds possessing broad-spectrum potency were prepared.

Identification and optimization of anthranilic sulfonamides as novel, selective cholecystokinin-2 receptor antagonists.

A high throughput screening approach to the identification of selective cholecystokinin-2 receptor (CCK-2R) ligands resulted in the discovery of a novel series of antagonists, represented by 1-[2-[(2,1,3-benzothiadiazol-4-ylsulfonyl)amino]-5-chlorobenzoyl]-piperidine (1; CCK-2R, pK(I) = 6.4). Preliminary exploration of the structure-activity relationships around the anthranilic ring and the amide and sulfonamide moieties led to a nearly 50-fold improvement of receptor affinity and showed a greater than 1000-fold selectivity over the related cholecystokinin-1 receptor.