29211-43-6Relevant academic research and scientific papers
Iodine-catalyzed oxidative annulation: Facile synthesis of pyrazolooxepinopyrazolones: Via methyl azaarene sp3C-H functionalization
Zhang, Xin-Ke,Miao, Xiao-Yu,Zhou, Yu,Wang, Yu-Mei,Song, Ying-Chun,Liu, Hang,Xiong, Yi-Lu,Li, Ling-Yu,Wu, An-Xin,Zhu, Yan-Ping
supporting information, p. 1236 - 1242 (2022/02/19)
An iodine-catalyzed methyl azaarene sp3 C-H functionalization has been developed for the synthesis of a seven-membered O-heterocyclic architecture containing three different heterocyclic aromatic hydrocarbons. This method can be applied to a wide range of substituted methyl azaarenes and diverse 2,4-dihydro-3H-pyrazol-3-ones, and brings about the efficient preparation of 2,9-dihydrooxepino[2,3-c:6,5-c′]dipyrazol-3(7H)-ones in high yields with the merits of low catalyst loading, good functional group tolerance and metal-free conditions.
Electrochemical synthesis of versatile ammonium oxides under metal catalyst-, exogenous-oxidant-, and exogenous-electrolyte-free conditions
Yuan, Yong,Li, Liang-Sen,Zhang, Lin,Wang, Feng,Jiang, Lin,Zuo, Lin,Wang, Qi,Hu, Jian-Guo,Lei, Aiwen
supporting information, p. 2768 - 2771 (2021/03/23)
An electrochemical oxidative cross-coupling reaction between 2.5-substituted-pyrazolin-5-ones and ammonium thiocyanate has been developed, which resulted in a series of unprecedented cross-coupling products under metal catalyst-, exogenous-oxidant-, and exogenous-electrolyte-free conditions. It is worth noting that since the resulting cross-coupling products are nearly insoluble in MeCN, the pure product could be afforded without silica gel column purification. In addition, the prepared ammonium oxides are versatile building blocks for synthesizing functionalized pyrazole derivatives.
Metal-Free Direct C–H Thiolation and Thiocyanation of Pyrazolones
Kittikool, Tanakorn,Yotphan, Sirilata
supporting information, (2020/02/13)
Metal-free approach for direct C–H thiolation and thiocyanation of N-substituted pyrazolones with disulfides and thiocyanate salts, respectively, are developed. These reactions allow the C–S bond coupling to proceed effectively under mild conditions, providing useful and convenient methods for preparation of a series of 4-thio-substituted pyrazolone analogues, which have potential applications in organic, medicinal and material chemistry. Preliminary mechanistic investigation suggested that radical processes are likely to involve in these transformations.
Copper-catalyzed acylation of pyrazolones with aldehydes to afford 4-acylpyrazolones
Xiao, Yan,Wu, Xiaopeng,Teng, Jiangang,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
supporting information, p. 7552 - 7557 (2019/08/20)
Copper-catalyzed direct acylation of the alkenyl C-H bond in 1,2-dihydro-3H-pyrazol-3-ones has been developed, affording a series of 4-acylpyrazolones in moderate to good yields. Notably, this protocol involves readily accessible substrates and reagents, which have good functional group tolerance leading to pyrazolone derivatives under mild reaction conditions.
DABCO-catalyzed silver-promoted direct thiolation of pyrazolones with diaryl disulfides
Thupyai, Akkharaphong,Pimpasri, Chaleena,Yotphan, Sirilata
supporting information, p. 424 - 432 (2018/02/06)
A highly efficient protocol for a direct thiolation of N-substituted pyrazolones with diaryl disulfides is described. Using a combination of DABCO and silver(i) acetate, the C-S bond formation proceeds smoothly at room temperature under mild and easy to handle conditions. This synthetic strategy offers a convenient and direct modification of antipyrine and other pyrazolone substrates, giving a series of aryl sulfide-substituted pyrazolone products in moderate to excellent yields.
One pot synthesis of 3-methyl-1-phenyl-4-3′-methyl-1-phenyl-4′, 5′-dihydro-5′-oxopyrazol-4′-yl-pyrazolo [5, 4- d]-4H-1-benzopyran derivatives
Akbarzadeh, Abolfath,Taheri, Milad,Zare, Mina
, p. 342 - 347 (2015/05/27)
A one pot synthesis of Pyrazolo [5, 4-d] benzopyrans through condensation of 2-pyrazolin-5-ones and ortho hydroxy benzaldehydes has been described. The synthesized solid products after purification were identified and approved by 1H-NMR spectro
Direct and enantioselective vinylogous michael addition of α-alkylidenepyrazolinones to nitroolefins catalyzed by dual cinchona alkaloid thioureas
Rassu, Gloria,Zambrano, Vincenzo,Pinna, Luigi,Curti, Claudio,Battistini, Lucia,Sartori, Andrea,Pelosi, Giorgio,Casiraghi, Giovanni,Zanardi, Franca
supporting information, p. 2330 - 2336 (2014/07/21)
While several protocols exist for the asymmetric functionalization of pyrazolinones at the α-position relying on nucleophilic addition or annulation procedures, use of α-alkylidene electron-rich analogues in asymmetric vinylogous coupling to carbon electrophiles is substantially an uncharted domain. We now report, for the first time, that alkylidenepyrazolinones carrying an enolizable carbon at the γ-position efficiently participate in direct and asymmetric, catalytic vinylogous Michael-type additions to nitroolefins providing the expected adducts in high yields, with complete γ-site selectivity and with extraordinary levels of enantio-, diastereo-, and geometrical selectivities. Both enantiomeric adducts were equally accessed by employing a quasi-enantiomeric quinine- or quinidine-based thiourea catalyst pair.
Synthesis of some novel pyrazolopyridooxazine, pyrazoloquinolizines, pyrazoloindolizine and pyrazolopyranopyrimidinone derivatives
Al-Tilasi, Hissah H.,El-Baih, Fatma E.M.
, p. 3896 - 3902 (2014/08/05)
Different pyrazolone derivatives were prepared as starting materials for the synthesis of pyrazolopyridooxazine, pyrazoloquinolizines, pyrazoloindolizine, 1,4-oxazinopyrazolines and pyrazolopyranopyrimidinone derivatives via reactions with different reagents applying the one pot multicomponent reaction using microwave and ultrasound irradiation in some cases.
Base initiated aromatization/CO bond formation: A new entry to O-pyrazole polyfluoroarylated ethers
Tang, Xiangyang,Chang, Jing,Liu, Cuibo,Zhang, Bin
supporting information, p. 6534 - 6537 (2015/01/08)
A base initiated intermolecular SNAr reaction of pyrazolones with polyfluoroarenes was developed. The process involved the isomerization aromatization of pyrazolone followed by the CO bond formation via the selective CF bond cleavage. With this strategy, a wide range of O-pyrazole polyfluoroarylated ethers bearing diverse functional groups were synthesized in mild to good yields. Additionally, our method was also applied to the isoxazol substrates.
Tungstophosphoric acid-catalyzed synthesis of pyrazolones in water
Min, Zhen-Li,Hu, Xia-Min
, p. 7290 - 7292 (2013/08/23)
A convenient and efficient method for the synthesis of pyrazolones via condensation of hydrazine derivatives with β-keto esters in water catalyzed by tungstophosphoric acid is described. It eliminates the need to dry solvents and substrates before use and the products are easily isolated with high yields.
