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Сагитуллина, Г. П.; Glizdinskaya, L. V.; Sitnikov, G. V.; Sagitullin, R. S.

doi:10.1023/a:1022174325051

Cited by 10 publications

(12 citation statements)

References 6 publications

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“…Compounds Ib-IIIb were synthesized as described in [4], 1,4-dihydropyridine Ie was prepared by the procedure reported in [6], and benzoylacetonitrile was obtained according to [11]. The synthesis of cyanopyridine IIe was described in [12], and of pyridinium methyl sulfate IIIh, in [10]. …”

Section: Methodsmentioning

confidence: 99%

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Cyanopyridines. Synthesis and Recyclization of Their Quaternary Salts

et al. 2005

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3-Cyanopyridines containing an acetyl, ester, nitro, or cyano group in the 5-position were synthesized via various versions of the Hantzsch reaction. Recyclization of quaternary pyridinium salts by the action of aqueous-alcoholic alkali afforded 2-methylaminopyridine derivatives and 6-methylamino-3-nitro-2,4-diphenylbenzonitrile. R = 4-ClC 6 H 4 (a), 4-MeOC 6 H 4 (b), 2,4-(MeO) 2 C 6 H 3 (c), 2-furyl (d), Me (e).In continuation of our studies on recyclization of pyridinium salts having a cyano group in position 3 [1-3] we synthesized previously unknown cyanopyridines IIa-IIg with a view to examine the effect of structural and electronic factors on the direction of recyclization of quaternary salts derived therefrom. Symmetrically substituted 3,5-dicyanopyridines IIaIIe were obtained by cyclocondensation of 3-amino-2-butenenitrile with various aldehydes (HantzschMeyer-Mohr reaction), by analogy with the synthesis of 3,5-dicyanopyridines reported previously [4-6]. 1,4-Dihydropyridines Ia-Ie were oxidized with sodium nitrite in acetic acid. Both stages in the synthesis of pyridines IIa-IIe (Scheme 1) were characterized by fairly high yields. 5-Acetyl-6-methyl-2-phenylpyridine-3-carbonitrile (IIf) was prepared by three-component condensation of benzoylacetonitrile, triethyl orthoformate, and 4-amino-3-penten-2-one at a ratio of 1 : 3 : 1 at 70°C. Under these conditions, addition of the β-carbon atom in the enamine fragment of 4-amino-3-penten-2-one to ethoxymethylene derivative of benzoylacetonitrile gave rise to a new carbon-carbon bond and closure of pyridine ring [7, 8] (Scheme 2). The synthesis of ethyl 5-cyano-2-methyl-4-phenylpyridine-3-carboxylate (IIg) included structural modification of previously described ethyl 5-cyano-2-methyl-6-oxo-4-phenyl-1,6-dihydropyridine-3-carboxylate [9] via nucleophilic replacement of the hydroxy group by chlorine and subsequent reductive dechlorination (Scheme 3). NitroMe 2 SO 4 , NaClO 4 N NC Me CN Me R IIIa-IIIe Me ClO 4 RCHO + 2 CN H 2 N Me N H NC Me CN Me R NaNO 2 , AcOH N NC Me CN Me R Ia-Ie IIa-IIe Scheme 1.

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Section: Methodsmentioning

confidence: 99%

“…pyridine IIh was obtained by us previously [10]. The alkylation of weakly basic pyridines IIa-IIh was effected with the aid of dimethyl sulfate.…”

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Cyanopyridines. Synthesis and Recyclization of Their Quaternary Salts

et al. 2005

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“…2-Methyl-5-nitro-4,6-diphenylnicotinic acid (10). A mixture of ethyl 2-methyl-5-nitro-4,6-diphenylnicotinate [26] (1.45 g, 4 mmol), ethanol (10 ml), KOH (1.12 g, 20 mmol) in water (2 ml) was boiled for 3-4 h, diluted with water and acidified with conc. HCl to pH 3, the precipitate was filtered off and recrystallized.…”

Section: -mentioning

confidence: 99%

NitropyridineS. 9*. Synthesis of substituted 3-amino-5-nitropyridines

Сагитуллина

Garkushenko

Glyzdinskaya

et al. 2011

Chem Heterocycl Comp

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The discovery of bacteriostatic activity of Sulfidine was the stimulus for the study of the chemistry of isomeric aminopyridines with the objective of converting them into promising sulfamide preparations [2].Aminopyridines with nitrogroups on the pyridine nucleus have been insufficiently well studied, which is explained by their low accessibility. Exceptions are 2-amino-3-nitro-and 5-nitropyridines and their derivatives, which are accessible thanks to the activity of 2-aminopyridine to electrophilic substitution [3]. The number of publications connected with the preparation of substituted 3-amino-5-nitropyridines is limited to those describing the synthesis of 3-amino-5-nitropyridine [4-7], 3-amino-2-methyl-5-nitropyridine [8], and 3-amino-5-nitrocollidine [9].The objective of the present work was the synthesis of the previously unknown 3-amino-5-nitropyridines 2a,b, 4, 6b,c, and 9a-c based on the available nitropyridines 1a,b, 3a-c, and 7a-c which contain acetyl, amide, and carboxyl groups at position 3 of the pyridine nucleus, The choice of the variant of the sextet rearrangement in the synthesis of 3-amino-5-nitropyridines was determined by the availability of the corresponding 5-nitropyridines. 3-Amino-5-nitropyridines 2a,b were obtained by the Schmidt reaction starting from 3-acetyl-5-nitropyridines 1a,b by a one-stage synthesis which we had developed earlier [10,11]: N Ac O 2 N Me R N NH 2 R Me O 2 N 1. NaN 3 , H 2 SO 4 2. H 2 O,  1a,b 2a,b 1,2 a R = Me, b R = Ph

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“…It is based on the reaction of β-keto ester with aldehyde and ammonia [1]. Modifications of this reaction were reported, where β-diketones, malonic acid esters, β-keto acids, β-aminocrotononitrile, ethyl cyanoacetate, and cyanoacetamide were used instead of β-keto esters [2].…”

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Synthesis of N 3,N 5,4-triaryl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamides

2011

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The known Hantzsch dihydropyridine synthesis is convenient for the preparation of 1,4-dihydropyridine derivatives having similar substituents in positions 2/6 and 3/5. It is based on the reaction of β-keto ester with aldehyde and ammonia [1]. Modifications of this reaction were reported, where β-diketones, malonic acid esters, β-keto acids, β-aminocrotononitrile, ethyl cyanoacetate, and cyanoacetamide were used instead of β-keto esters [2]. While continuing studies in this field, we were the first to perform reactions of N-arylacetoacetamides with aromatic aldehydes and ammonia with a view to obtain new 1,4-dihydropyridine derivatives. The reactions were carried out by heating the reactants in boiling alcohol over a period of 3 h, and the products were the corresponding N 3 ,N 5 ,4-triaryl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamides Ia-If.Compounds Ia-If were isolated as light yellow crystalline substances which were soluble in DMF, DMSO, and hot ethanol and insoluble in water. The IR spectra of Ia-If contained absorption bands due to stretching vibrations of the amide carbonyl group (1656-1688 cm -1 ), double C=C bonds (1600-1632 cm -1 ), amide NH groups (3264-3312 cm -1 ), and NH group in the pyridine ring (3348-3408 cm -1 ). Compounds Ia-If displayed in the 1 H NMR spectra signals from protons in the aromatic rings and substituents therein, a six-proton singlet from two methyl groups (δ 2.24-2.45 ppm) a singlet from the 4-H proton in the pyridine ring (δ 4.84-5.05 ppm), a signal from the N 1 H proton (δ 7.95-8.50 ppm), and a twoproton signal from amide NH groups (δ 9.21-9.25 ppm). In the mass spectrum of Id we observed the molecular ion peak and peaks of fragment ions which were consistent with the assumed structure.2,6-Dimethyl-N 3 ,N 5 ,4-triphenyl-1,4-dihydropyridine-3,5-dicarboxamide (Ia). A mixture of 39 g (0.22 mol) of acetoacetanilide, 10.16 ml (0.1 mol) of benzaldehyde, 8 ml (0.11 mol) of concentrated aqueous ammonia, and 60 ml of ethanol was heated for 3 h under reflux, 40 ml of warm water was added, the mixture was cooled and treated with 60% aqueous ethanol, and the precipitate was filtered off and recrystallized from ethanol. Yield 6.5 g (15%), mp >300°C. IR spectrum, ν, cm -1 : 3408, 3272 (NH); 1680 (C=O); 1652 (C=C). 1 H NMR spectrum, δ, ppm: 2.02 s (6H, CH 3 ), 4.89 s (1H, 4-H), 7.03 m (15H, H arom ), 8.00 s R 1 = R 2 = H (a); R 1 = 2-MeO, R 2 = H (b); R 1 = H, R 2 = 4-Cl (c); R 1 = H, R 2 = 3-O 2 N (d); R 1 = H, R 2 = 4-O 2 N (e); R 1 = H, R 2 = 2-Cl (f).

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Cited by 10 publications

References 6 publications

Cyanopyridines. Synthesis and Recyclization of Their Quaternary Salts

Cyanopyridines. Synthesis and Recyclization of Their Quaternary Salts

NitropyridineS. 9*. Synthesis of substituted 3-amino-5-nitropyridines

Synthesis of N 3,N 5,4-triaryl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamides

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