Studies with Azinylacetonitriles: 2-Pyridylacetonitrile as a Precursor to Functionally Substituted Pyridines

Abstract

2-Pyridylacetonitrile (1) couples with aromatic diazonium salts to yield arylhydrazones 2a-c, that were shown to exist in the syn-form 2 rather than the anti-form 4. Compounds 2a,c reacted with hydroxylamine in refluxing DMF to yield the interesting 1,2,3-triazolylpyridines 6. Attempts to cyclize 2 to give the corresponding fused pyrazolopyridines 9 failed. On the other hand, compound 1 condensed with dimethylformamide dimethyl acetal to yield enaminonitrile 10 that could be converted into pyrazolylpyridine 11.

The effect of resonance-assisted hydrogen bond on the second-order nonlinear optical properties of pyridine hydrazone photoswitches: a quantum chemistry investigation

“…The observed variations in Z isomers are a result of the presence of intramolecular N1–H⋯N6 hydrogen bonding, leading to the formation of a quasi-ring structure N1–N2–C3–C4–N6⋯H (the distance N1–N6 and H⋯N6 is ∼2.691 and 1.922 Å, respectively). According to the literature and our calculations, this quasi-ring structure is almost planar 58–65 (see Table S2, ESI†) and distinguished by short N1–N6 distances and longer H–N1 bonds ( r HN 1 , Z ≈ 1.018 Å and r HN 1 , E ≈ 1.012 Å). Furthermore, analysis using QTAIM indicates a delocalization of electrons within the quasi-cycle closed (RCP).…”

Novel Imidazole‐based Hydrazonoyl Cyanides and Amidrazones Containing N(N,O)‐Heterocycles: Selective Synthesis, Reaction Mechanisms and Preliminary Anticancer Evaluation

“…The main approach is based on the coupling reaction between nitrile derivatives and aromatic diazonium salts, which is usually performed in ethanol and under sodium acetate catalysis. [28][29][30] Nevertheless, the scope of these reactions is restricted to the synthesis of the Narylhydrazones due to the experimental difficulties associated with the manipulation of aliphatic diazonium salts. The synthesis of arylhydrazonoyl cyanides through Pd catalized dehydrogenation reaction of α-hydrazinonitriles has also been reported.…”

“…On the other hand, hydrazonoyl cyanides have attracted significant interest in medicinal chemistry as they have been widely used as synthetic precursor for pyrazoles, 1,2,3‐triazoles and 1,2,4‐triazoles, [28] yet limited methods can be found in the literature for the synthesis of these highly functionalized synthetic precursors. The main approach is based on the coupling reaction between nitrile derivatives and aromatic diazonium salts, which is usually performed in ethanol and under sodium acetate catalysis [28–30] . Nevertheless, the scope of these reactions is restricted to the synthesis of the N ‐arylhydrazones due to the experimental difficulties associated with the manipulation of aliphatic diazonium salts.…”

Behavior of 2-cyano-3-(dimethylamino)-N-(4-phenylthiazol-2-yl)acrylamide towards some nitrogen nucleophiles

“…[1][2][3][4][5][6][7][8][9][10] Several novel syntheses of azoles, azines, and azoloazines utilizing enaminonitriles as starting components have been reported by Elnagdi and coworkers. [11][12][13][14] On the other hand, the considerable biological and medicinal activities of thiazoles and those linked to different heterocycles through a carboxamide linkage initiated a considerable recent interest in the development of syntheses of these molecules. [15][16][17][18][19] These compounds were found to be associated with a wide range of chemotherapeutic activities.…”