Reaction of imidazole series aldeydes with bis[2-(2-pyridyl)ethyl]-phosphine chalcogenides: Synthesis of polyfunctional heterocyclic systems

Abstract

The nucleophilic addition of bis [2-(2-pyridyl)ethyl]phosphine sulfide and bis [2-(2-pyridyl)-ethyl]phosphine selenide to 2-formyl-1-organylimidazoles and benzimidazoles occurs efficiently without catalysis at room temperature to give functionalized heterocyclic compounds containing imidazole, benzimidazole, and pyridine rings and also chalcogenophosphoryl and hydroxyl groups.Polyheterocyclic systems constructed using nitrogen heterocycles continue to be intensively studied as biologically active compounds, efficient polydentate ligands for designing metall complexes, and are widely used as reactive building blocks for organic synthesis. Thus triazolyl-, thiadiazolyl-, and oxadiazolylpyridines are known as amplifiers of fleomycin [1], some ketolides with imidazolylpyridine fragments are active antibiotics [2], functional imidazolylpyridines with fluorophenyl [3] or sulfinyl [4] groups show antiviral activity, and also affect processes occurring involving kinase [3,5]. Metal-complex catalysts [6-10], ionic liquids which are successfully used, in particular, in the Heck reaction [9], and special materials [6,7] can be produced based on imidazolylpyridines.Functional heterocyclc systems have special value. Thus imidazoles and benzimidazoles containing chalcogenophosphoryl and hydroxyl functions are efficient ligands for directing the synthesis of promising biologically active metal complexes [11][12][13][14] and also as models for studying several physicochemical aspects [12][13][14]. One of the convenient routes for the synthesis of functional heterocyclic groups can be the reaction of the secondary pyridylphosphine chalcogenides 1, 2 with 2-formyl-1-organylimidazoles 3, 4 and -benzimidazoles 5, 6.The aim of this work was direct synthesis of novel heterocyclic systems containing imidazole and pyridine nuclei and also hydroxyl and chalcogenophosphoryl functions by a study of the reaction of the aldehydes 3-6 with the available bis[2-(2-pyridyl)ethyl]phosphine sulfide (1) [15] and the previously unreported _______ * Dedicated to Professor A. Pozharskii on his 70th jubilee __________________________________________________________________________________________ A. E.

Synthesis of chalcophosphinic acid amides with pyridine rings*

“…13 C NMR spectrum, δ, ppm (J, Hz): 13.8 (CH 3 ); 20.0 (CH 2 Me); 31.3 (CH 2 Et); 31.6 (PyCH 2 ); 32.6 (d, 1 J P-C = 56.5, CH 2 P); 46.4 (NCH 2 ); 121.2 (C-5 Py); 122.9 (C-3 Py); 136.2 (C-4 Py); 149.1 (C-6 Py); 160.2 (d, 3 J P-C = 16.1, C-2 Py). 15 N NMR spectrum, δ, ppm: -70.5 (N, Py), -342.6 (P-N). 31 P NMR spectrum, δ, ppm (J, Hz): 74.0 (satellite d, 1 J P-Se = 727.9, P=Se).…”

“…The starting secondary phosphine chalcogenides 1-3 were obtained by a chlorine-free method from red phosphorus, 2-vinylpyridine, and the elemental chalcogens [13][14][15][16].…”