Arylsulfonamide pyrimidines as VLA-4 antagonists

Novel Ligands Targeting α4β1 Integrin: Therapeutic Applications and Perspectives

Among the other members of the adhesion molecules' family, α4β1 integrin, a heterodimeric receptor, plays a crucial role in inflammatory diseases, cancer development, metastasis and stem cell mobilization or retention. In many cases, its function in pathogenesis is not yet completely understood and investigations on ligand binding and related stabilization of active/inactive conformations still represent an important goal. For this reason, starting from the highlight of α4β1 functions in human pathologies, we report an overview of synthetic α4β1 integrin ligands under development as potential therapeutic agents. The small molecule library that we have selected represents a collection of lead compounds. These molecules are the object of future refinement in academic and industrial research, in order to achieve a fine tuning of α4β1 integrin regulation for the development of novel agents against pathologies still eluding an effective solution.

The Design of Potent, Selective and Drug-Like RGD αvβ1 Small-Molecule Inhibitors Derived from non-RGD α4β1 Antagonists

Up to 45 % of deaths in developed nations can be attributed to chronic fibroproliferative diseases, highlighting the need for effective therapies. The RGD (Arg-Gly-Asp) integrin αvβ1 was recently investigated for its role in fibrotic disease, and thus warrants therapeutic targeting. Herein we describe the identification of non-RGD hit small-molecule αvβ1 inhibitors. We show that αvβ1 activity is embedded in a range of published α4β1 (VLA-4) ligands; we also demonstrate how a non-RGD integrin inhibitor (of α4β1 in this case) was converted into a potent non-zwitterionic RGD integrin inhibitor (of αvβ1 in this case). We designed urea ligands with excellent selectivity over α4β1 and the other αv integrins (αvβ3, αvβ5, αvβ6, αvβ8). In silico docking models and density functional theory (DFT) calculations aided the discovery of the lead urea series.

Regioselective Control of the SNAr Amination of 5-Substituted-2,4-Dichloropyrimidines Using Tertiary Amine Nucleophiles

The SNAr reaction of 2,4-dichloropyrimidines, further substituted with an electron-withdrawing substituent at C-5, has selectivity for substitution at C-4. Here we report that tertiary amine nucleophiles show excellent C-2 selectivity. In situ N-dealkylation of an intermediate gives the product that formally corresponds to the reaction of a secondary amine nucleophile at C-2. This reaction is practical (fast under simple reaction conditions, with good generality for tertiary amine structure and moderate to excellent yields) and significantly expands access to pyrimidine structures.