Aqueous media preparation of 2-amino-4,6-diphenylnicotinonitriles using cellulose sulfuric acid as an efficient catalyst

Experimental and theoretical studies of the nanostructured {Fe3O4@SiO2@(CH2)3Im}C(CN)3catalyst for 2-amino-3-cyanopyridine preparationviaan anomeric based oxidation

“…Among the pyridine ring systems which present varied chemotherapeutic and pharmacological applicabilities [4][5][6], 2-amino-3-cyanopyridines raised substantial medicinal and synthetic attentionssince this widespread heterocycle molecules allowed an access to many demonstrated bio-active species such as IKK-b inhibitors [7], A 2A adenosine receptor antagonist [8], and potent inhibitor of HIV-1 integrase [9]. Hence, in consequence of the aforementioned biological significances of these versatile structural motifs, a number of procedures have been reported on this topic like microwave or ultrasound irradiation [10][11][12][13], hexadecyldimethyl benzyl ammonium bromide and triethylamine [14], DMF [15], acetic acid [16], Fe 3 O 4 [17], Cellulose-SO 3 H [18]and using earth Lewis acid catalyst [19]. Although, several catalyst and protocol have been studied for the preparation of the 2-amino-3-cyanopyridine derivatives, the methods suffer from one or more imperfection such as toxic solvent like benzene [20], multi-steps reaction pathway [21], high temperature and microwave assistance [22,23], prolonged reaction times and harsh reaction conditions with low yields.…”

Synthesis of bioactive heterocycles using reusable heterogeneous catalyst HClO4–SiO2 under solvent-free conditions

“…All reagents and solvents were purchased from commercial sources such as Merck and Aldrich and were used as received. 1 H NMR (400 MHz) and 13 C NMR (75 MHz) spectra were recorded on FT-NMR spectrometer using CDCl 3 and d 6 -DMSO. Chemical shifts δ are measured in parts per million (ppm) and are relative to tetramethylsilane (TMS) as the internal reference.…”

“…Solid-supported reagents are expected to be performed better than the individual reagent because of the increased effective surface area of the reagent, their activity and selectivity (4). Among the solid-supported catalytic systems, perchloric acid adsorbed on silica gel (HClO 4 -SiO 2 ) is found in various organic functional group transformations and also in the synthesis of many bioactive heterocycles (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). Among the heterocycles, coumarins or chromenes are an important class of benzopyrones being the core unit of different natural products (16).…”

“…H NMR (300 MHz, CDCl 3 , δ ppm): 7.37-7.42(m, 1H), 7.45-7.56(m, 3H),7.59-7.66(m, 3H), 7.68-7.71(m, 1H),7.94-7.96(m, 2H);13 C NMR (75.5 MHz, CDCl 3 , δ ppm): 116.7, 119.9, 125.9, 128.6, 128.7, 129.6, 133.2, 133.6, 133.9, 135.6, 139.1, 157.3, 192.3, 193.6; IR (KBr) (ν max, cm −1 ) :1246, 1604, 1662, 3032, 3052 cm −1 ; MS: m/z = 266 (M + ). Anal.…”

Contemporary development in sequential Knoevenagel, Michael addition multicomponent reaction for the synthesis of 4-Aryl-5-oxo-5H-indeno[1,2-b]pyridine-3-carbonitrile

“…A number of homogeneous as well as heterogeneous catalysts [57][58][59][60][61][62][63][64][65][66][67][68] have been employed for the preparation of pyridines, dihydropyridines, and its analogs in diverse methods, e.g. acid [69,70], base [71,72], microwave synthesis [58], ionic liquid [73,74], etc., are cited in literature, but they have their own merits and demerits. It has been evidenced that in most of the cases, the synthesis of the N-containing skeleton is carried out by using ammonium salts as an N-source, but in the absence of an ammonium salt, aromatic aldehyde, malononitrile, and 1,3-diketone react to give a pyran derivative [75][76][77].…”