15419-64-4Relevant academic research and scientific papers
A modified and practical synthetic route to indazoles and pyrazoles using tungstate sulfuric acid
Rahmatzadeh, S. Setareh,Karami, Bahador,Khodabakhshi, Saeed
, p. 17 - 20 (2015/02/19)
Tungstate sulfuric acid-catalyzed Knorr reaction have been used as a simple, rapid, atom economic and green method for the synthesis of indazole and pyrazole derivatives based on the condensation of hydrazine derivatives and ss-dicarbonyl compounds under solvent-free conditions. It was found that the catalyst could be recovered and reused without significant loss of its activity. The use of this method provides a novel and improved modification of Knorr synthesis in terms of clean reaction profile, use of a safe catalyst and solvent-free conditions. A green method for the synthesis of indazole and pyrazole derivatives from the condensation of hydrazine derivatives with dicarbonyl compounds has been described. Tungstate sulfuric acid (TSA) catalyzed efficiently the reactions to give good yields.
Layered zirconium sulfophenyl phosphonate as heterogeneous catalyst in the synthesis of pyrazoles and 4,5,6,7-tetrahydro-1(2)H-indazoles
Curini, Massimo,Rosati, Ornelio,Campagna, Valerio,Montanari, Francesca,Cravotto, Giancarlo,Boccalini, Mauro
, p. 2927 - 2930 (2007/10/03)
Pyrazoles and tetrahydroindazoles may be prepared by condensation of 1,3-diones and hydrazines under layered zirconium sulfophenyl phosphonate catalysis, in solvent-free conditions. Georg Thieme Verlag Stuttgart.
