- Diversity-Oriented Synthesis of Spiropentadiene Pyrazolones and 1 H-Oxepino[2,3- c]pyrazoles from Doubly Conjugated Pyrazolones via Intramolecular Wittig Reaction
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An efficient method for the diversity-oriented synthesis of spiropentadiene pyrazolones and 1H-oxepino[2,3-c]pyrazoles is reported. The methodology attributes O-acylation of phosphorus zwitterions which were formed by a tandem phospha-1,6-addition of PBu3 to α,β,γ,δ-unsaturated pyrazolones, further generating betaine intermediates that preferentially resulted in the aforementioned cyclic products in a diversity-oriented manner. The mechanistic investigations revealed that formation of the betaines is the key step to provide the products via an intramolecular Wittig reaction or an unprecedented δ-C-acylation/cyclization/Wittig reaction.
- Khairnar, Pankaj V.,Wu, Chi-Yi,Lin, Yi-Fang,Edukondalu, Athukuri,Chen, Yi-Ru,Lin, Wenwei
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supporting information
p. 4760 - 4765
(2020/06/25)
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- Viable and straightforward approach to the preparation of water soluble pyrazol-5-one derivatives through glycoconjugation
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The synthesis of water soluble pyrazol-5-one azo-dyes has been achieved. 6′-Aminolactosetriacetonide 9 was selected as the key building block to glyconjugate the pyrazole ring at its 3 position via a carboxamide or via a benzeneamide moiety in position 1 of the heterocycle. Diethyl-3-oxopentandionate 2 led eventually to a bicyclic compound, hampering the glyconjugation coupling process. The values of the molar extinction coefficients (ε) confirmed the tendency of pyrazolone azo dyes to exist in their tautomeric hydrazo form (especially in polar solvents); whereas the presence of substituents on the phenylazo group influenced the visible absorption maxima negligibly.
- Bianchini, Roberto,Bonanni, Marco,Corsi, Massimo,Infantino, Angela Simona
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p. 8636 - 8644
(2012/10/29)
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- DRUGS COMPRISING COMBINATION OF ANTITHROMBOTIC AGENT WITH PYRAZOLONE DERIVATIVE
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It is intended to provide drugs for treating and/or preventing ischemic diseases which are safe and have little side effects. Namely, drugs comprising a combination of an antithrombotic agent and a pyrazolone derivative defined in the description or its pharmaceutically acceptable salt.
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- Transformations of alkyl (5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)acetates into 5-heteroaryl-3-oxo-2-phenyl-3,5-dihydro-2H-pyrazolo[4,3-c] pyridine-7-carboxylates
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Alkyl [(Z)-4-dimethylaminomethylidene-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl] acetate (4) was transformed with N- and C-nucleophiles into alkyl [4-(substituted amino)methylidene-4,5-dihydro-1H-pyrazol-3- yl] acetates (7) and alkyl (4-heteroarylmethylidene-4,5-dihydro-1H -pyrazol-3-yl)acetates (8), respectively. Compounds (7) cyclize by heating with DMFDMA in DMF into 2H-pyrazolo[4,3-c]pyridine-7-carboxylates (9).
- Bevk, David,Jak?e, Renata,Svete, Jurij,Golobi?, Amalija,Goli?, Ljubo,Stanovnik, Branko
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p. 197 - 223
(2007/10/03)
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