545445-35-0Relevant academic research and scientific papers
Pyrrolo[3,4-c]pyrazole Synthesis via Copper(?) Chloride-Catalyzed Oxidative Coupling of Hydrazones to Maleimides
Zhu, Jia-Nan,Wang, Wen-Kang,Jin, Ze-Hui,Wang, Qian-Kun,Zhao, Sheng-Yin
supporting information, p. 5046 - 5050 (2019/09/03)
A variety of pyrrolo[3,4-c]pyrazole derivatives from readily available aldehyde hydrazones and maleimides via direct oxidative coupling under radical cascade reaction have been reported. This method offers satisfactory chemical yields and good functional
Method for preparing drug Apixaban for preventing or treating venous thrombus after joint replacement
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Paragraph 0028; 0034; 0038; 0042; 0045, (2017/06/02)
The invention discloses a method for preparing a drug Apixaban for preventing or treating venous thrombus after joint replacement. The method comprises the steps as follows: 1) p-tolylhydrazine and ethyl glyoxylate are subjected to a reaction by catalysis of cuprous bromide in the presence of an alkali and are filtered after the reaction is completed, a borane-methyl sulfide complex is added to a filtrate, a compound shown as the formula I is then added for stirred and mixed reaction, and a reaction mixture L is obtained; 2) the reaction mixture L obtained in the step 1) is stirred under the acidic condition; 3) 1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxopiperidine-1-yl 3)phenyl]-4,5,6,7-tetrahydro-1H-pyrazole[3,4-c]pyridine-3-carboxylate in the step 1) is subjected to ammonolysis, and Apixaban with the formula shown in the specification is obtained. The method for preparing Apixaban has the advantages of mild condition and higher yield, a pyrazole ring product is generated with a one-pot method, the process is easier, the cost is greatly reduced, and the diazo-reaction widely adopted in the prior art is avoided.
Silver(I)-Catalyzed Tandem Sigamatropic Rearrangement/1,3-H Shift/6π Aza-electrocyclization of N-Propargylic Hydrazones: A Mild Synthetic Route to 1,6-Dihydropyridazines
Ding, Zong-Cang,Ju, Lu-Chuan,Yang, Ying,An, Xiao-Ming,Zhou, Yun-Bing,Li, Ren-Hao,Tang, Hai-Tao,Ding, Cheng-Ke,Zhan, Zhuang-Ping
, p. 3936 - 3941 (2016/05/24)
A highly efficient AgOTf catalyzed [3,3] sigmatropic rearrangement/1,3-H shift/6' aza-electrocyclization cascade reaction of N-propargylic hydrazones has been developed. This method provides a new mild synthetic route to various polysubstituted 1,6-dihydr
Palladium and Copper Cocatalyzed Intermolecular Cyclization Reaction: Synthesis of 5-Aminopyrazole Derivatives
Ma, Chaowei,Wen, Ping,Li, Jihui,Han, Xu,Wu, Zhaoyang,Huang, Guosheng
supporting information, p. 1073 - 1077 (2016/04/09)
A novel and efficient palladium and copper co-catalyzed intermolecular cyclization of acetonitriles with hydrazones has been developed for the synthesis of 5-aminopyrazoles through C-C and C-N bond formation. The reaction has the advantages of easily avai
Vinylogous reactivity of enol diazoacetates with donor-acceptor substituted hydrazones. Synthesis of substituted pyrazole derivatives
Xu, Xinfang,Zavalij, Peter Y.,Hu, Wenhao,Doyle, Michael P.
, p. 1583 - 1588 (2013/03/28)
A regiospecific synthesis of multifunctional pyrazoleshas been developed from a cascade process triggered by Rh(II)-catalyzed dinitrogen extrusion from enol diazoacetates with vinylogous nucleophilic addition followed by Lewis acid catalyzed cyclization a
Catalytic asymmetric construction of chiral hydropyridazines via conjugate addition of N-monosubstituted hydrazones to enones
Wu, Wenbin,Yuan, Xiaoqian,Hu, Juan,Wu, Xinxin,Wei, Yuan,Liu, Zunwu,Lu, Junzhu,Ye, Jinxing
supporting information, p. 4524 - 4527 (2013/09/24)
The first example of a highly enantioselective and scalable formal diaza-ene reaction between N-monosubstituted hydrazones and enones catalyzed by a simple chiral primary-second diamine salt has been developed. The catalytic process provides a highly prac
Pyrolysis of 3-hydroxy-2-arylhydrazonoalkanoic acid derivatives
Al-Awadi, Nouria A.,Ibrahim, Yehia A.,John, Elizabeth,Parveen, Aneesha
, p. 1298 - 1307 (2011/04/15)
1,2-Diaza-1,3-butadienes have been obtained from readily available 3-hydroxy-2-arylhydrazonopropanoates under various reaction conditions including pyrolysis, dehydration under Mitsunobu conditions or with acetic anhydride or acetic acid. According to their method of synthesis these 1,2-diaza-1,3- butadienes underwent subsequent reactions to give interesting products, and in the presence of proper dienophiles gave the corresponding cycloaddition products. Also, a new approach to pyrazole-3-carboxylic acid derivatives was discovered during an attempt to dehydrate 3-hydroxy-2-arylhydrazonobutanoic esters.
