4-Aryl-2-anilinopyrimidines as corticotropin-releasing hormone (CRH) antagonists

A Platform for the Liebeskind-Srogl Coupling of Heteroaromatic Thioethers for Medicinal-Chemistry-Relevant Transformations

General and robust conditions for the Liebeskind-Srogl coupling were developed and used in functionalization of medicinal-chemistry-relevant heterocyclic substrates. Applicability in HTE and library synthesis, combined with its orthogonality to other cross-coupling reactions, make it highly attractive for discovery chemistry workflows. Additionally, the results suggest that the nature of the Cu(I)-carboxylate plays a more prominent role in the reaction performance than the nature of Pd-catalysts, which is rather uncommon for Pd-catalysis and can be used in further optimization of Liebeskind-Srogl coupling.

Antitubercular 2-Pyrazolylpyrimidinones: Structure-Activity Relationship and Mode-of-Action Studies

Phenotypic screening of a Medicines for Malaria Venture compound library against Mycobacterium tuberculosis (Mtb) identified a cluster of pan-active 2-pyrazolylpyrimidinones. The biology triage of these actives using various tool strains of Mtb suggested a novel mechanism of action. The compounds were bactericidal against replicating Mtb and retained potency against clinical isolates of Mtb. Although selected MmpL3 mutant strains of Mtb showed resistance to these compounds, there was no shift in the minimum inhibitory concentration (MIC) against a mmpL3 hypomorph, suggesting mutations in MmpL3 as a possible resistance mechanism for the compounds but not necessarily as the target. RNA transcriptional profiling and the checkerboard board 2D-MIC assay in the presence of varying concentrations of ferrous salt indicated perturbation of the Fe-homeostasis by the compounds. Structure-activity relationship studies identified potent compounds with good physicochemical properties and in vitro microsomal metabolic stability with moderate selectivity over cytotoxicity against mammalian cell lines.

Discovery and SAR studies of novel 2-anilinopyrimidine-based selective inhibitors against triple-negative breast cancer cell line MDA-MB-468

Triple-negative breast cancers (TNBCs) are characterized as an invasive and intractable subtype of breast cancers. Overexpression of epidermal growth factor receptor (EGFR) has been considered to be an important target for TNBC therapy, but efficacies of EGFR inhibitors in clinical trials are elusive. In this study, novel series of 2-anilinopyrimidines were synthesized in an effort to identify selective inhibitors against an EGFR-overexpressing TNBC cell line. Biological evaluation demonstrated that compounds 21 and 38, with a 4-methylpiperidine group and a high ClogP value, exhibited good potency and selectivity for the TNBC cell line. This study has provided evidence to support further development of 2-anilinopyrimidine-based TNBC selective inhibitors and investigation of the targets of compounds 21 and 38.

Site-selective Suzuki-Miyaura coupling of heteroaryl halides - understanding the trends for pharmaceutically important classes

Suzuki-Miyaura cross-coupling reactions of heteroaryl polyhalides with aryl boronates are surveyed. Drawing on data from literature sources as well as bespoke searches of Pfizer's global chemistry RKB and CAS Scifinder® databases, the factors that determine the site-selectivity of these reactions are discussed with a view to rationalising the trends found.

One-pot Double Suzuki Couplings of Dichloropyrimidines

An effective one-pot, regioselective double Suzuki coupling of 2,4-dichloropyrimidine has been developed, which enables the quick and efficient synthesis of diarylated pyrimidines. The choice of solvent proved critical to the success of this reaction sequence, with alcoholic solvent mixtures affording much greater reactivity and correspondingly lower temperatures than the use of polar aprotic solvents.

CRHR1 Receptor binding and lipophilicity of pyrrolopyrimidines, potential nonpeptide corticotropin-releasing hormone type 1 receptor antagonists

A series of compounds related to N-butyl-N-ethyl[2,5,6-trimethyl-7-(2,4,6-trimethylphenyl)pyrrolo[2,3-d]pyrimidin-4-yl]amine (1, antalarmin) have been prepared and evaluated for their CRHR1 binding affinity as the initial step in the development of selective high affinity hydrophilic nonpeptide corticotropin-releasing hormone type 1 receptor (CRHR1) antagonists. Calculated log P (Clog P) values were used to evaluate the rank order of hydrophilicity for these analogues. Introducing oxygenated functionalities (delta-hydroxy or bis-beta-ethereal) into 1 gave more hydrophilic compounds, which had good affinity for the receptor. Introducing an amino group or shortening the alkyl side chain was detrimental to CRHR1 affinity. The alcohol 4-[ethyl[2,5,6-trimethyl-7-(2,4,6-trimethylphenyl)pyrrolo[2,3-d]pyrimidin-4-yl]amino]butan-1-ol (3), bearing a terminal hydroxyl group on an N-alkyl side-chain, showed the highest CRHR1 binding affinity among these compounds (K(i)=0.68 nM), and is one of the highest affinity CRHR1 ligands known. Compounds 3-5, and 8, which are likely to be less lipophilic than 1, have high CRHR1 affinity and may be valuable probes to further study the CRH system.

Use of the Suzuki reaction for the synthesis of aryl-substituted heterocycles as corticotropin-releasing hormone (CRH) antagonists

The Suzuki reaction has been used to synthesize a variety of aryl-substituted heterocyclic antagonists of the CRH1 receptor. Examples with several different heterocyclic cores are potent CRH receptor ligands.