75640-14-1Relevant academic research and scientific papers
PTSA-catalyzed Mannich-type-cyclization-oxidation tandem reactions: One-pot synthesis of 1,3,5-substituted pyrazoles from aldehydes, hydrazines and alkynes
Liu, Pei,Pan, Ying-Ming,Xu, Yan-Li,Wang, Heng-Shan
, p. 4696 - 4698 (2012)
A convenient one-pot Mannich-type-cyclization-oxidation tandem process has been developed for the synthesis of 1,3,5-trisubstituted pyrazoles derivatives from aldehydes, hydrazines and alkynes using p-toluenesulfonic acid monohydrate (PTSA) as a multifunctional catalyst. This method provides a flexible and rapid route to 1,3,5-trisubstituted pyrazoles.
Synthesis and characterization of 1,3,5-triarylpyrazol-4-ols and 3,5-diarylisoxazol-4-ols from chalcones and theoretical studies of the stability of pyrazol-4-ol toward acid dehydration
Cipagauta Esquivel, Edna Carolina,Rufino, Virgínia Camila,Trindade Nogueira, Matheus Henrique,Carbonaro Souza, Ana Carolina,Pliego Júnior, Josefredo Rodriguez,Valle, Marcelo Siqueira
, (2019/12/23)
The synthesis of diverse pyrazol-4-ol and isoxazole-4-ol heterocycles involving only 3 reaction steps is reported in this study. However, the synthesis of carboxamide pyrazol-4-ol has failed in the conditions used in the synthesis, acid methanol solution. The carboxamide pyrazol-4-ol decomposes via dehydration, forming the respective pyrazol. Theoretical calculations were used to elucidate the dehydration reaction. We have found a mechanism for acid-catalyzed dehydration that can explain the experimental observations. The calculated free energy profile for acid-catalyzed dehydration of the carboxamide pyrazol-4-ol and phenylpyrazole-4-ol point out that the latter is more stable in relation dehydration, with a dehydration rate 100 times smaller in acid methanol solution.
Photooxidation of 3,5-diaryl-1-phenyl-2-pyrazolines: Experimental and computational studies
Soltani, Marzieh,Memarian, Hamid Reza,Sabzyan, Hassan
, (2019/12/23)
Photooxidation of various 2-pyrazolines is studied experimentally and computationally. Experimental results show that the electron-donating/withdrawing substituents increases/decreases the rate of this photoreaction. The proposed light-induced electron-tr
A convenient and efficient protocol for the synthesis of 5-aryl-1,3-diphenylpyrazole catalyzed by hydrochloric acid under ultrasound irradiation
Li, Ji-Tai,Yin, Ying,Li, Ling,Sun, Ming-Xuan
experimental part, p. 11 - 13 (2010/11/16)
The synthesis of 5-aryl-1,3-diphenylpyrazole via the reactions of 3-aryl-2,3-epoxy-1-phenyl-1-propanone with phenylhydrazine was carried out in 69-99% yields at room temperature under ultrasound irradiation. This method provides several advantages such as
Solvent-free synthesis of 1, 3-diphenyl-5-arylpyrazole derivatives
Li, Ji-Tai,Yin, Ying,Meng, Xian-Tao
experimental part, p. 384 - 386 (2010/04/23)
The synthesis of 1, 3-diphenyl-5-arylpyrazoles via the reactions of 2, 3-epoxy-1-phenyl-3-aryl-1-propanones with phenylhydrazine was carried out in 48-84% yields at 230 °C under solvent-free condition within 1.5 h. This method provides several advantages
REGIOCHEMISTRY OF THE CYCLOADDITIONS OF DIPHENYLNITRILIMINE TO COUMARIN, 3-ETHOXYCARBONYL AND 3-ACETYL COUMARINS. A REINVESTIGATION
Fathi, Toufik,Dinh An, Nguyen,Schmitt, Gerard,Cerutti, Ernest,Laude, Bernard
, p. 4527 - 4536 (2007/10/02)
The cycloaddition reactions of diphenylnitrilimine to coumarin, 3-ethoxycarbonyl and 3-acetylcoumarins were studied.The observed regiochemistry of the reaction with the coumarin 4a was the same as the one suggested by other researchers.For the coumarins 4
