Synthesis of o‐Nitrosoacylbenzenes from o‐Nitrobenzyl Alcohols and Their Derivatives.

Gazzaeva, R. A.; Федотов, А. Н.; Трофимова, Е. В.; Попова, О. А.; Mochalov, S. S.; Зефиров, Н. С.

doi:10.1002/chin.200639083

Cited by 3 publications

(3 citation statements)

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“…1-(7-Nitro-2,3-dihydro-1,4-benzodioxin-6-yl)butan-1-one was obtained by the nitration of 1-(2,3-dihydro-1,4-benzodioxin-6-yl)butan-1-one with acetyl nitrate in Ac 2 O as described in [29]. Yield 84%; mp 90-91 o C (EtOH).…”

Section: Methodsmentioning

confidence: 99%

Synthesis of quinolin-2-ones by an intramolecular Knoevenagel condensation and by tandem Michael–Knoevenagel heterocyclization

Mochalov

Chasanov

Федотов

et al. 2011

Chem Heterocycl Comp

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Compounds containing the quinolin-2-one fragment have already been studied systematically as subjects of medicobiological investigations for more than 50 years. Since then it was discovered that quinolin-2-ones as structural units, form part of the composition of a series of natural alkaloids [1]. The investigations led to a remarkable result, but only in practically the last 10-12 years, when new biological targets were discovered and test systems based on them were designed and in practice highly coeffective screening was embodied in the search for new medicinals. It was established that derivatives of quinolin-2-ones may display properties of nonsteroidal selective androgen modulators [2-4] and may show effective action against hepatitis B [5], act as inhibitors of acyl coenzyme A and cholesterol acyltransferase and increase the permeability of calcium activated K + channels [6, 7], display high antiproliferative activity [8][9][10][11] and the ability to bind to 5-HT 3 receptors [12], to receptors of antibiotics [13], and are inhibitors of various types of kinase [14][15][16][17], of farnesyl transferase [18], and affect erectile dysfunction [19]. The established broad spectrum of biological activity of quinolin-2-ones derivatives studied up to the present time, on the one hand, stimulated the search of new medicinals of various profile based on them, and on the other, made urgent the problem of synthesizing new representatives of this class with the prospect of developing for them characteristic forms of biological activity and the potential of using them for practical purposes.For the synthesis of new derivatives of quinolin-2-ones, we turned to the Knoevenagel intramolecular condensation using as precursor the corresponding derivatives of ortho-aminoacylbenzenes. This route to the synthesis of quinolin-2-one, comprising the heterocyclization of 2-(acetylamino)acetophenone under the action of aqueous alcoholic alkaline solution, was used for the first time in [20]. However, many years passed before a series of quinolin-2-ones was synthesized in a similar manner [21,22]. In all probability, insufficient attention to this method of synthesis was linked with the difficulties of obtaining the starting ortho-aminoacylbenzenes.

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Section: Methodsmentioning

confidence: 99%

Synthesis of quinolin-2-ones by an intramolecular Knoevenagel condensation and by tandem Michael–Knoevenagel heterocyclization

Mochalov

Chasanov

Федотов

et al. 2011

Chem Heterocycl Comp

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“…Yield 72%; bp 103-104°C (9 mmHg), n D 20 1.5810. 2-Acetyl-5-tert-butylnitrosobenzene (11) was synthesized as described in [40]. Yield 87%; mp 140-143°C (ethanol).…”

Section: Methodsmentioning

confidence: 99%

A new effective route for the synthesis of substituted 2h-indazoles

Mochalov

Khasanov

Трофимова

et al. 2009

Chem Heterocycl Comp

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A two-stage synthesis of 2H-indazoles has been established, based on consecutive reactions of reduction of 2-alkyl-, 2-cyclopropyl-, and 2-arylcarbonylazobenzenes to phenylazo-substituted benzyl alcohols and intramolecular heterocyclization of the reduction products under the influence of organic acids.In recent years there has been a considerably strengthened interest in the synthesis and study of the medicobiological properties of derivatives of 2H-indazoles, resulting from the observation in a series of compounds which are seldom encountered in nature, a class of heterocycles with a wide range of biological activity: antiangiogenic [1], anticarcinogenic and anti-inflammatory [2,3], antimicrobial [4], antifungal [5,6], cytotoxic [7], and antihelminthic [8]. In addition compounds of this class show potential as inhibitors of NO-synthetases [9, 10], protein kinases [11,12], tubulin [13], modulators of X-receptors of the liver [14], and they also show properties of male contraceptives [15,16].The discovery of the biological activity of the 2H-indazoles caused the real problem of the synthesis of new derivatives of this class of heterocycles. It is important to underline that at present a wide range of precursors has been used to synthesize the 2H-indazole ring, in practice including all strategic routes for its synthesis. For example, 2H-indazoles have been synthesized from 2-azidobenzylideneamines [17] or 2-azidobenzoylamines [18,19], oxidative cyclization from N-acylhydrazones of 2-aminoacylbenzenes [20,21], reaction of carbenes with azobenzene [22,23], rearrangement of ortho-substituted azobenzenes [24,25], and reductive heterocyclization of ortho-nitrobenzylideneamines [26][27][28], and heterocyclization of ortho-nitrobenzylamines [29][30][31][32][33]. A variant of the formation of the 2H-indazole system from compounds containing the pyrazole unit have been described. For example, oxidation of 4,5-tetramethylenepyrazoles with dichlorodicyanobenzoquinone gave substituted 2H-indazoles in high yield [34]. However, despite the abundance of variants for the construction of the 2H-indazole ring, the variation of substituents is practically limited to those in positions 2 and 3, and only in the papers [30,31,33] were syntheses of 2H-indazoles containing substituents in the annelated benzene ring reported.

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“…However, studies have recently appeared showing that this problem may be circumvented, sometimes by well-known reactions, and the desired 2-aminoacylbenzenes may be obtained in high yield. For example, the reported acid-catalyzed rearrangement of variously substituted 2-nitrophenylcyclopropanes 1 and 2 gives 2-nitrosopropiophenones 3 and 4, which may be transformed to yield a broad range of 2-aminopropiophenones 6-8 [8][9][10] (10), which is the product of the nitration of 1-(4-tert-butylphenyl)ethanol (9), undergoes a similar rearrangement to give 4-tert-butyl-2-nitrosoaceto-phenone (11) [11]. We are the first to report the synthesis of 2-amino-4-tert-butylacetophenone (12) by the reduction of 11.…”

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confidence: 99%