85302-22-3Relevant academic research and scientific papers
Synthesis of 4-aroyl-5-arylpyrazoles and 4-aroyl-3-arylpyrazoles via the reaction of enaminodiketones with substituted hydrazines
Choshi, Tominari,Hatae, Noriyuki,Hibino, Satoshi,Kotouge, Rika,Nishiyama, Takashi,Oikawa, Tsutomu,Ono, Kanako,Yamauchi, Akira
, p. 25 - 45 (2020/01/28)
Pyrazole is a five-membered heterocyclic compound and is one of the important heterocycles in the fields of medicine and pharmacology. Here, we demonstrate the reactivity of symmetrical enaminodiketones 8–14 with substituted hydrazines. When using alkylhy
Synthesis of 4-Acylpyrazoles from Saturated Ketones and Hydrazones Featured with Multiple C(sp3)-H Bond Functionalization and C-C Bond Cleavage and Reorganization
Tian, Miaomiao,Shi, Xiaonan,Zhang, Xinying,Fan, Xuesen
, p. 7363 - 7372 (2017/07/26)
In this paper, an efficient and convenient one-pot synthesis of diversely substituted 4-acylpyrazole derivatives via copper-catalyzed one-pot cascade reactions of saturated ketones with hydrazones is reported. Mechanistically, the formation of the title compounds involves the in situ formation of an enone intermediate through the dehydrogenation of a saturated ketone and the [2 + 3] cyclization of the enone with hydrazone followed by an aromatization-driven C-C bond cleavage and reorganization. To our knowledge, this is the first example in which the biologically and pharmaceutically important yet otherwise difficult-to-obtain 4-acylpyrazole derivatives are directly prepared from saturated ketones and hydrazones featured with multiple aliphatic C-H bond functionalization and C-C bond cleavage and reorganization. Compared with literature methods, this novel process has advantages such as simple and economical starting materials, a sustainable oxidant, excellent regioselectivity, and good efficiency.
Photoreactivity of 4-nucleophile-substituted isoxazoles
Donati, Donato,Fusi, Stefania,Ponticelli, Fabio
, p. 329 - 334 (2007/10/02)
The photoreactivity of 1a-1c under steady-state irradiation has been examined and the photoproducts characterized.Several heterocycloes were obtained: 1a gave the pyrrazolines 6 and 7 and the triazine 8; 1b yielded the azetidine 9 and the imidazole 10; 1c gave the imidazole 10, the piperazine 15, the aziridine 16 and the pyrazole 19.In addition, open-chain products were obtained, i.e., the methylaminovinyl ketone 12 from 1b and the enaminones 17 and 18 from 1c.While the formation of most of the products can be explained via the expected intermediate ketenimines, azirines and nitrile ylides, new pathways are involved in the formation of the isoxazole 13 and the pyrazole 19 from 1c
Benzoyl phenyl 1-methylpyrazoles. Synthesis, characterization, and spectra
Kano, Kunio,Scarpetti, David,Warner, John C.,Anselme, Jean-Pierre,Springer, James H.,Arison, Byron H.
, p. 2211 - 2219 (2007/10/02)
The synthesis and unequivocal characterization of all six isomers of benzoyl phenyl 1-methylpyrazole (2) are described.The isomer of 2 isolated as one of the products of the reaction of 1,1-dimethyl-1-phenacylhydrazinium bromide (1) with base was shown to be only previously reported isomer, 5-benzoyl-3-phenyl-1-methylpyrazole (2b).
Reaction of 2-Dimethylaminomethylene-1,3-diones with Dinucleophiles. I. Synthesis of 1,5-Disubstituted 4-Acylpyrazoles
Schenone, Pietro,Mosti, Luisa,Menozzi, Giulia
, p. 1355 - 1361 (2007/10/02)
Reaction of open-chain and cyclic sym-1,3-diones with N,N-dimethylformamide dimethyl acetal gave, generally in high yield, a series of sym-2-dimethylaminomethylene-1,3-diones which reacted with phenylhydrazine and methylhydrazine to afford, generally in satisfactory yield, a number of 1,5-disubstituted 4-acylpyrazoles.The applications and limits of this new pyrazole synthesis are presented and discussed.
