Synthesis of some novel bioactive 4-oxy/thio substituted-1H-pyrazol-5(4H)-ones via efficient cross-Claisen condensation

A novel pyrazolone, 4,4-dichloro-1-(2,4-dichlorophenyl)-3-methyl-5-pyrazolone, as a potent catalytic inhibitor of human telomerase.

The bifunctional pyrazolopyridine (2) and pyrano-pyrazole (3) derivatives were prepared by the reaction of 2-(2,4-dinitrophenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one (1) with p-methoxybenzaldehyde, malononitrile in the presence of ammonium acetate or piperidine, respectively. Compound 2 was used as the key intermediate to prepare the pyrazolo-pyrido-pyrimidine derivatives through its reaction with formic acid, formamide-formic acid-DMF, ammonium thiocyanate or reaction with triethyl orthoformate followed by cyclization with hydrazine hydrate. Reaction of 3 with triethyl orthoformate followed by cyclization with hydrazine hydrate gave the pyrazolo-pyrano-pyrimidine derivative 11. Reaction of ethyl-3-oxo-2-[2-phenyl-diazenyl]butanoate and ethyl 2-[2-(4-chlorophenyl)diazenyl]-3-oxobutanoate with 1 to give the pyrazolone derivatives 13a and 13b, was also considered.

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Synthesis of some new annulated pyrazolo-pyrido (or pyrano) pyrimidine, pyrazolopyridine and pyranopyrazole derivatives.

A facile four-component sequential protocol in the expedient synthesis of novel 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones in water and their antitubercular evaluation.

Sonochemically synthesis of pyrazolones using reusable catalyst CuI nanoparticles that was prepared by sonication

Pyrazolone derivative 3 was prepared by the nucleophilic addition of 2,5-diphenyl-2,4-dihydro-3H-pyrazol-3-one (1) to chalcone (2). Reaction of 3 with hydrazine hydrate, phenylhydrazine, hydroxylamine hydrochloride, p-chlorobenzaldehyde, acetyl chloride and phosphorus pentasulfide afforded the corresponding hydrazone, phenylhydrazone, oxime, arylidene, O-acetyl and dithio derivatives. Pyrazolone 1 was condensed also with cyclohexanone and aromatic aldehydes; the behaviour of the obtained arylidene derivatives towards hydrazines, cyclohexanone, malononitrile and urea was also investigated. Some of the new compounds showed antimicrobial and antifungal activities.

Mohamed Ali Al-Haiza

Papers

Synthesis and potential antimicrobial activity of some new compounds containing the pyrazol-3-one moiety