Synthesis, structural and conformational properties, and gas phase reactivity of 1,4-dihydropyridine ester and ketone derivatives

Abstract

A new series of 4-aryl-2,6-dimethyl-1,4-dihydropyridines, characterized by ester or ketone functions at positions 3 and 5, has been synthesized. Structural and conformational properties, concerning the dihydropyridine ring and the orientation (synplanar/antiperiplanar) of the substituents have been investigated in their crystal structure and in solution by nuclear magnetic resonance. Evaluation of intermolecular and hydrogen bonding interactions as well as packing features, have been also carried out, evidencing interesting packing motifs. Their gas phase reactivity, as protonated and deprotonated molecules, has been investigated by electrospray ionization, high resolution and collision-induced dissociation multiple stage mass spectrometry. Deydrogenation reactions have been observed as a function of the capillary voltage.

Diethyl 2,6-dimethyl-4-(naphthalen-1-yl)-1,4-dihydropyridine-3,5-dicarboxylate

“…data reports the title compound. The bond lengths and angles in the title compound are in good agreement with the corresponding values in closely related structures (Fun et al, 2012;Vrá bel et al, 2005;Giorgi et al, 2010;Metcalf & Holt, 2000).…”

Physical-chemical and in silico Studies of 1,4-dihydropyridine Derivatives

“…Similarly, 1,4-DHP derivatives containing cationic (pyridinium) substituents at positions 2 and 6 and carboxyl groups at positions 3 and 5 have not been fully characterized by physical chemistry and spectroscopic methods. As shown in the literature, some 1,4-DHP derivatives with the ketone groups at positions 3 and 5 have intramolecular hydrogen bonds, and the biological activity of 1,4-DHP derivatives is related to the type of conformers, the nature of the substituents and their mutual orientation [18].…”