- Reaction of aryl and heterocyclyhydrazines with 2-methylchromone: Structural investigation of the products
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Reaction of 2-methylchromone (2) with phenylhydrazine provides 3-methyl-5-(o-hydroxyphenyl)-1-phenylpyrazole (6) as a major product. In contrast under similar conditions, heterocyclyhydrazines (8a-c) yield exclusively 5-ethyl-3-(o-hydroxyphenyl)-1-heterocyclylpyrazoles (9a-c). The structural assignments are based on an unambiguous synthesis and an analysis of NMR (1H and 13C) spectral data.
- Singh, Shiv P.,Kumar, Dalip,Kumar, Devinder
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- Benzopyrans: Part XX - 4-Oxo-4H-benzopyran-3-carbonitrile/Carboxylic Acid: Change of Their Reaction Courses by a Methyl Substituent at 2-Position
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2-Methyl-4-oxo-4H-benzopyran-3-carbonitriles (1b) and the corresponding carboxylic acids (2b), unlike their 2-unsubstituted analogues (1a) and (2a), give with phenyl hydrazine the hydrazones (6b) and the pyrazoles (13b), respectively.The hydrazones (6b) have been converted into the benzopyranopyrazoles (8b).
- Ghosh, Chandra Kanta,Pal, Chandana
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p. 1288 - 1290
(2007/10/02)
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- INVESTIGATIONS IN THE CHROMONE SERIES. PART XI. REACTIONS OF METHYLCHROMONES AND METHYL-4-THIOCHROMONES WITH PHENYLHYDRAZINE
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Reactions of 6-methyl-, 2-methyl- and 2,8-dimethylchromones, as well as of 6-methyl-, 8-methyl- and 2,8-dimethyl-4-thiochromones with phenylhydrazine have been investigated.A lack of reactivity in thiocarbonyl group in 4-thiochromone system has been established.Intermediate products of reactions have been separated, their structure established and the reaction course described.
- Kostka, Krzysztof,Nawrot-Modranka, Jolanta
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p. 1341 - 1348
(2007/10/02)
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- Synthesis of Some Imidazole- and Pyrazole- Derived Chelating Agents
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Procedures involving condensation of o-phenylenediamines with carboxylic acids, and reaction of bifunctional alkyl halides with bifunctional nucleophiles are described.Syntheses are reported of 2,6-bis(2-benzimidazyl)-pyridine, 1,3-bis(2-benzimidazyl)-2-thiapropane, 1,7-bis(2-benzimidazyl)-2,6-dithiaheptane, 2-hydroxymethyl-5,6-dimethylbenzimidazole, 2-chloromethyl-5,6-dimethylbenzimidazole hydrochloride, 1,7-bis(5,6-dimethyl-2-benzimidazyl)-2,6-dithiaheptane, 3,6-bis(1-pyrazolyl)pyridazine, 2-(2-hydroxy-3-methylphenyl)benzimidazole, 2-(2-hydroxyphenyl)benzimidazole, 5-(2-hydroxyphenyl)-3-methyl-1-phenylpyrazole, 3(5)-(2-hydroxyphenyl)-5(3)-methylpyrazole, 3(5)-(2-hydroxyphenyl)-5(3)-phenylpyrazole, and 1,3-bis((5-methylpyridyl)imino)isoindoline.
- Addison, Anthony W.,Burke, Philip J.
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p. 803 - 805
(2007/10/02)
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