Reaction Of Amidrazones Research Articles

Synthesis of quinone-based heterocycles of broad-spectrum anticancer activity

A synthesis of benzo[ e][1,2,4]triazines and 1,2,4-triazolospiro[4,5]deca-2,6,9-trien-8-ones has been developed from reactions of amidrazones with 2-chloro-1,4-benzoquinone in EtOAc containing 0.5 mL of piperidine. This highly regioselective and one-pot process provided rapid access to 1,2,4-triazolospiro[4,5]deca-2,6,9-trien-8-ones (60%–70%) and benzo[ e][1,2,4]triazines (11%–18%). On reacting amidrazones with 5-hydroxy-1,4-naphthoquinone in an EtOAc/piperidine mixture, the reaction proceeded to give 5-hydroxy-2-(piperidin-1-yl)naphthalene-1,4-dione. The structures of the isolated products were proved by infrared, NMR (2D-NMR), mass spectra, and elemental analyses in addition to X-ray structure analysis. The reaction mechanisms are discussed. The anticancer screening of selected compounds showed broad-spectrum anticancer activity against most melanoma cancer cell lines, ovarian cancer OVCAR-3, central nervous system cancer SF-295 and U251, non-small cell lung cancer NCI-H23, renal cancer SN12C, and colon cancer HCT-15 and HCT-116. The selected compounds exhibited moderate to weak anticancer activity to other cell lines.

Regioselective formation of 1,2,4-triazoles by the reaction of amidrazones in the presence of diethyl azodicarboxylate and catalyzed by triethylamine.

A general method for the synthesis of 1,3,5-trisubstituted 1,2,4-triazoles has been developed from reaction of amidrazones with ethyl azodicarboxylate and triethylamine (Mitsunobu reagent) in EtOH. This highly regioselective one-pot process provides rapid access to highly diverse triazoles. The reaction was explained, based on Mitsunobu reagent oxidizing ethanol to acetaldehyde, which would then react with amidrazones to give the substituted 3-methyltriazoles. A [2 + 3] cycloaddition reaction between two oxidized forms of amidrazones produced the second type of triazoles. X-ray structure analyses proved the structure of each type of product.

One‐Pot Reaction of Amidrazones, Phthaloyl Chloride, and Triethyl Amine: Synthesis of 1‐(1′,2′,4′‐Triazole)‐2‐Benzoic Acid

One‐pot reaction of equimolar amounts of phthaloyl chloride and N‐aryl‐benzamidrazones in the presence of two equivalents of triethylamine (Et3N), gave at r.t. 4‐aryl‐3‐(o‐carboxyphenyl)‐5‐phenyl‐1,2,4‐triazoles in good yields. The structure of the obtained products was proved by IR, mass, NMR spectra, and elemental analyses. The mechanism of product formation is discussed.

Regioselective synthesis of 5-aminopyrazoles from reactions of amidrazones with activated nitriles: NMR investigation and X-ray structural analysis

N-Arylbenzamidrazones and ethyl 2-cyano-3-ethoxybut-2-enoate reacted together in ethanol and catalyzed by triethylamine (Et3N) to give 5-amino-3-methyl-1-(aryl(phenylimino)methyl)-1H-pyrazole derivatives. Reaction of the target amidrazones with bis-(methylthio)methylidene)malononitrile in EtOH/Et3N/DMF mixture proceeded to give the corresponding 5-aminopyrazoles. The structure of the obtained products was proved by IR, mass, and NMR spectra and elemental analyses. Two-dimensional NMR spectroscopy and X-ray structural analyses were used to differentiate the assigned structures from other possible ring systems and regioisomers. The reaction mechanism is discussed.

Reaction of Amidrazones with 2,3-Diphenylcyclopropenone: Synthesis of 3-(aryl)-2,5,6-Triphenylpyrimidin-4(3H)-ones

Amidrazones react with 2,3-diphenylcyclopropenone to give 3-aryl-2,5,6-triphenylpyrimidin-4(3H)-one derivatives in good yields. The synthesised compounds were characterised by spectroscopic tools and their structures confirmed by X-ray crystallography. A rational mechanism of formation of the products is presented.

Reaction of Amidrazones with Phthaloyl Chloride—Synthesis of 1,2,4‐Triazolium Salts (Part I)

Phthaloyl chloride reacts with N‐arylbenzamidrazones to give 1,2,4‐triazolium salts in very good yields. The mechanism described the products formation was discussed. The structure of the obtained products was proved by IR, mass, NMR spectra, and elemental analyses.

Reaction of Amidrazones with Diaminomaleonitrile: Synthesis of 4‐Amino‐5‐Iminopyrazoles

Diaminomaleonitrile and N‐arylbenzamidrazones reacted together to give 4‐amino‐5‐iminopyrazoles. A probable reaction mechanism involves firstly removal of ammonia, followed by addition and cylization of the hydrazino‐N2 of amidrazone to the nitrile group in diaminomaleonitrile. The structure of the obtained products was proved by IR, mass, NMR spectra and elemental analyses.

Implanting Nitrogen into Hydrocarbon Molecules through CH and CC Bond Cleavages: A Direct Approach to Tetrazoles

The development of novel methods for the preparation of tetrazoles is of long-standing interest and a challenge for organic chemists because of the importance of these compounds in chemistry and biology. In particular, 1,5-disubstituted tetrazoles are very useful compounds in medicinal chemistry and important synthetic intermediates. In the past several decades, some general strategies for the synthesis of 1,5-disubstituted tetrazoles from functionalized starting materials have been developed (Scheme 1). These methods include: a) the reactions of ketones or oximes with sodium azide and hydrogen azides, b) the reactions of amides with sodium azides in the presence of phosphorus(V) chloride or triflic anhydride and the reactions of amidrazones with dinitrogen tetroxide or nitrous acid, c) the reactions of imidoyl chlorides or imidoylbenzotriazoles with sodium azides and, d) the reactions of nitriles with alkyl azides. These developed methods significantly improved the synthesis of tetrazoles, but these approaches have some limitations, such as the use of protic acid catalysts, tedious workups, and the use of functionalized starting materials, hence encouraging scientists to discover new strategies. The direct transformation of hydrocarbon molecules by transition-metal-catalyzed selective C H and C C bond activation (cleavage) has attracted considerable attention, owing not only to its fundamental scientific appeal but also to its potential utility in organic synthesis. A direct approach to tetrazoles through C H and C C bond cleavages of simple hydrocarbon molecules is still an extremely attractive yet challenging goal. Herein, we demonstrate a novel and efficient Cu-promoted implanting of nitrogen into simple hydrocarbon molecules to construct 1, 5-disubstituted tetrazoles through C H and C C bond cleavages, and C N bond formation under mild and neutral reaction conditions (Scheme 1e). Azide has been widely used as a useful aminating reagent in organic synthesis. The application of azides for the direct synthesis of aryl nitriles and alkenyl nitriles through C H bond cleavage has been recently reported. Recent achievements on the functionalization of C H and C C bonds encouraged us to try the direct synthesis of

Studies on pyrazine derivatives LII: Antibacterial and antifungal activity of nitrogen heterocyclic compounds obtained by pyrazinamidrazone usage

AbstractUsing reactivity of pyrazinamidrazones and their N′‐substituted derivatives 1–8 in reaction with sulfonyl chlorides sulfone derivatives 9–17 were obtained, with orthoformate cyclized to sulfonyl compounds 18–20. Amidrazones in reaction with pyraziniminoesters gave dihydrazidines 21–23, which cyclized to 3,5‐dipyrazine derivatives of 1,2,4‐triazole 24–26. 1‐Methyl‐ or 1‐phenyl‐3‐pyrazine‐1,2,4‐triazole 27–38 was formed in reaction of amidrazones 1–8 with orthoformate and orthoacetate or benzoyl chloride. N′‐Phenylamidrazones 3, 8 in reaction with thionyl chloride were transformed to 1,2,3,5‐thiatriazole S‐oxides 39, 40. Obtained compounds exhibited low antibacterial activity. Antifungal activity was affirmed for compounds 1, 3, 4, 5, 8, 37, 39, and 40, for which minimal inhibitory concentration (MIC) was in the concentration range of 16–128 μg/mL. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:49–58, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20751

Rapid and Facile Synthesis of Spiro[Indole-3,3′-[1,2,4]Triazol]-2(1H)-Ones

Various 4′-aryl-5′-phenyl-2′,4′-dihydrospiro[indole-3,3′-[1,2,4]triazol]-2(1H)-ones have been synthesised by reaction of amidrazones with 2-(2-oxoindolin-3-ylidene)malononitrile.

ChemInform Abstract: Reaction of Amidrazones with 1,4‐Diphenylbut‐2‐yne‐1,4‐dione.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Rapid and Facile Synthesis of 4‐Aryl‐5‐imino‐3‐phenyl‐1H‐naphtho[2,3‐f]‐1,2,4‐triazepine‐6,11‐diones via the Reaction of Amidrazones with Dicyanonaphthoquinone.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reactions of amidrazones with 1,4-quinones

Syntheses of various benzoand naphtho-1,2,4-triazin-6(4H)-ones are formed in one step via the reactions of amidrazones with benzoand naphtho-1,4-quinones. In contrast, the reactions of amidrazones with 2,3,5,6-tetrachloro-1,4-benzoquinone or 2,3-dichloro-1,4-naphthoquinone produced the same indazoles, no matter what substituents were present on the nitrogen of the amidrazone.

Reaction of amidrazones with 1,4-diphenylbut-2-yne-1,4-dione

Various (2 Z)-2-({( E)[arylamino]phenylmethylene}hydrazono)-1,4-diphenylbutan-1,4-diones are obtained during the reaction of amidrazones with 1,4-diphenylbut-2-yne-1,4-dione (DBD) in boiling ethanol.

Amidrazones in the Synthesis of 1H-1,2,4-Triazoles

The syntheses of various 2-(4-aryl-2,4-dihydro-3-phenyl-1,2,4-triazol-3-ylidene)indan-1,3-diones are reported. The key to their successful synthesis depends on the reaction of amidrazones 1a - f with 2-(1,3-dioxoindan-2-ylidene)malononitrile (2).