A method for the preparation of highly functionalized 4-iodo-7-azaindazoles is reported. These valuable heterocycles are synthesized via condensation of 2-hydrazineylpyrimidines with various iodoalkynones followed by Diels-Alder/retro-Diels-Alder cyclization. The method is general to the formation of products with a variety of C, C, and C substituents while preserving the C iodide functional handle for further late-stage functionalization.
View Article and Find Full Text PDFWe report a diastereoselective, photocatalyst-free decarboxylative alkylation of (hetero)aryl sulfinimines using redox-active esters under blue light. High yields and diastereoselectivities can be achieved under mild conditions, and we demonstrate its utility as a synthetic method, especially for medicinal chemists.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFSelective inhibitors of the GluN2B subunit of -methyl-d-aspartate receptors in the ionotropic glutamate receptor superfamily have been targeted for the treatment of mood disorders. We sought to identify structurally novel, brain penetrant, GluN2B-selective inhibitors suitable for evaluation in a clinical setting in patients with major depressive disorder. We identified a new class of negative allosteric modulators of GluN2B that contain a 1,3-dihydro-imidazo[4,5-]pyridin-2-one core.
View Article and Find Full Text PDFGlutamate mediates fast excitatory neurotransmission via ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. The trafficking and gating properties of AMPA receptors (AMPARs) can be amplified by transmembrane AMPAR regulatory proteins (TARPs), which are often expressed in localized brain regions. Herein, we describe the discovery, lead optimization, and preclinical characterization of 5-arylbenzimidazolone and oxindole-based negative modulators of AMPARs associated with TARP γ-8, the primary TARP found in hippocampus.
View Article and Find Full Text PDFThe preclinical characterization of novel octahydropyrrolo[3,4-c]pyrroles that are potent and selective orexin-2 antagonists is described. Optimization of physicochemical and DMPK properties led to the discovery of compounds with tissue distribution and duration of action suitable for evaluation in the treatment of primary insomnia. These selective orexin-2 antagonists are proven to promote sleep in rats, and this work ultimately led to the identification of a compound that progressed into human clinical trials for the treatment of primary insomnia.
View Article and Find Full Text PDFWe have recently completed the synthesis of 1-[2-(4-cyclobutyl-[1,4]diazepane-1-carbonyl)-4-(3-fluoro-phenoxy)-pyrrolidin-1-yl]-ethanone, a hydroxyproline-based H(3) receptor antagonist, on 100 g scale. The synthesis proceeds through four steps and route selection was driven by a desire to minimize the cost-of-goods. Naturally occurring trans-4-hydroxy-L-proline was chosen as the precursor to the target's core, which necessitated an inversion at both stereogenic centers.
View Article and Find Full Text PDFTreatment of oxazole or 5-aryl oxazoles with i-PrMgCl smoothly generates the corresponding 2-Grignard reagents, which react with Weinreb amides to provide exclusively 2-acyl oxazole products.
View Article and Find Full Text PDFIn an attempt to search for a new class of antibacterial agents, we have discovered a series of pyrazole analogs that possess good antibacterial activity for Gram-positive and Gram-negative organisms via inhibition of type II bacterial topoisomerases. We have investigated the structure-activity relationships of this series, with an emphasis on the length and conformation of the linker. This work led to the identification of tetrahydroindazole analogs, such as compound 1, as the most potent class of compounds.
View Article and Find Full Text PDFAn endocyclic restriction test for acid-catalyzed transfer of chlorine from a protonated chloroamine to an aromatic ring provides data that are consistent with a transition structure with a large bond angle between the entering and leaving groups around chlorine. These results rule out a dissociative mechanism or a mechanism that has an oblique angle between the entering and leaving groups.
View Article and Find Full Text PDFA η monomeric alkyllithium⋅(-)-sparteine complex has been isolated and characterized in the solid state (see picture). Determination of the absolute configuration of this key intermediate in asymmetric metalation/substitution sequences of N-tert-butoxycarbonyl-N-(p-methoxyphenyl)cinnamylamine allows definitive assignment of the stereochemical course of its electrophile-dependent substitution reactions.
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