Azole derivatives as histamine H3 receptor antagonists, Part I: Thiazol-2-yl ethers

A one-pot synthesis 3-alkoxycarbonyl-3,4-dihydro-2H-pyran-2-ones from vinylidene melderum's acids, dialkyl acetylenedicarboxylates, and simple alcohols

A one-pot synthesis of 3-alkoxycarbonyl-3,4-dihydro-2H-pyran-2-ones from intermolecular hetero-Diels-Alder reaction between vinylidene Melderum's acids and dialkyl acetylenedicarboxylates, in the presence of simple alcohols at room temperature, is described. The advantages of this procedure are good yields, short reaction time, and easy workup. Antioxidant properties of four derivatives of these 3,4-dihydro-2H-pyran-2-ones, together with their antimicrobial activities, are investigated.

Chemical Probes for Histamine Receptor Subtypes

Ligands with different properties and different selectivity are highly needed for in vitro and in vivo studies on the (patho)physiological influence of the chemical mediator histamine and its receptor subtypes. A selection of well-described ligands for the different receptor subtypes and different studies is shown with a particular focus on affinity and selectivity. In addition, compounds with radioactive or fluorescence elements will be presented with their beneficial use for other species or different investigations.

Design, synthesis, and biological evaluation of novel oxadiazole- and thiazole-based histamine H3R ligands

Histamine H₃ receptor (H₃R) is largely expressed in the CNS and modulation of the H₃R function can affect histamine synthesis and liberation, and modulate the release of many other neurotransmitters. Targeting H₃R with antagonists/inverse agonists may have therapeutic applications in neurodegenerative disorders, gastrointestinal and inflammatory diseases. This prompted us to design and synthesize azole-based H₃R ligands, i.e. having oxadiazole- or thiazole-based core structures. While ligands of oxadiazole scaffold were almost inactive, thiazole-based ligands were very potent and several exhibited binding affinities in a nanomolar concentration range. Ligands combining 4-cyanophenyl moiety as arbitrary region, para-xylene or piperidine carbamoyl linkers, and/or pyrrolidine or piperidine basic heads were found to be the most active within this series of thiazole-based H₃R ligands. The most active ligands were in silico screened for ADMET properties and drug-likeness. They fulfilled Lipinski's and Veber's rules and exhibited potential activities for oral administration, blood-brain barrier penetration, low hepatotoxicity, combined with an overall good toxicity profile.

Copper-catalyzed synthesis of thiazol-2-yl ethers from oxime acetates and xanthates under redox-neutral conditions

A copper-catalyzed [3+2] annulation of oxime acetates and xanthates to generate thiazol-2-yl ethers with good regioselectivity under redox-neutral conditions has been developed.

A novel series of N-(pyridin-2-yl)-4-(thiazol-5-yl)pyrimidin-2-amines as highly potent CDK4/6 inhibitors

AIM

Inhibitors of CDK4/6 have emerged as a powerful class of therapeutics for treatment of several malignancies. We herein describe the identification of a new series of molecules that demonstrated excellent selectivity for CDK4/6 over CDKs1, 7 and 9.

RESULTS

Medicinal chemistry optimization led to the discovery of 58 and 69 that inhibited CDK4 and CDK4/6, respectively, with high potency and selectivity, and 58 and 69 exhibited potent antiproliferative activities in a panel of human cancer cell lines including leukemia, and cancers of the breast, colon, ovary, pancreas and prostate.

CONCLUSION

Compounds 58 and 69 caused remarkable growth inhibition of melanoma cells, particularly the cells harboring multiple BRAF and NRAS mutations, via a CDK4/6-targeted mechanism of action. [Formula: see text].