One-pot efficient pseudo-five-components synthesis of 4,4′-(arylmethylene)bis(3-methyl-1-phenyl-1<i>H</i>-pyrazol-5-ols) at room temperature assisted by K<sub>2</sub>CO<sub>3</sub>
approach for the synthesis of 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ols) by an efficient one-pot reaction of aromatic aldehydes, phenylhydrazine, and ethyl acetoacetate by using substoichiometric amount of K2CO3 in acetonitrile solvent at room temperature is described. This protocol of one-pot synthesis produced a library of bis-pyrazolylmethane derivatives, a potential bioactive compound
Efficient pseudo five-component synthesis of 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1<i>H</i>-pyrazol-5-ol) derivatives promoted by a novel ionic liquid catalyst
作者:Zahra Abshirini、Abdolkarim Zare
DOI:10.1515/znb-2017-0179
日期:2018.4.25
resonance (NMR), 13C NMR, and mass and thermal gravimetric spectra). Thereafter, utilization of [TMEDSA][HSO4]2 as a highly effectual catalyst for the synthesis of 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol) derivatives through the one-potpseudofive-componentreaction of phenylhydrazine (2 eq.) with ethyl acetoacetate (2 eq.) and arylaldehydes (1 eq.) in relatively mild conditions,
Abstract Sulfuricacid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4′-alkylmethylene-bis(3-methyl-5-pyrazolones) in 74-90% yields. The heterogeneous catalyst was recycled and used in eleven
CELLULOSE SULFURIC ACID AS A NEW, BIODEGRADABLE AND ENVIRONMENTALLY FRIENDLY BIO-POLYMER FOR SYNTHESIS OF 4,4'-(ARYLMETHYLENE)BIS(3-METHYL-1-PHENYL-1H-PYRAZOL-5-OLS)
The one-pot multicomponent synthesis of 4,4`-arylmethylene-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol) was performed effectively by tandem Knoevenagel-Michael reaction of aryl aldehydes and 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one in the presence of a catalytic amount of cellulose sulfuric acid as an environmentally friendly biopolymer-based solid acid catalyst at reflux conditions. All of obtained compounds were characterized by FT IR, H-1 and C-13 NMR. This new methodology is of interest due to minimizing the cost operational hazards and environmental pollution, high yields, short reaction time, cost effective and simple work-up.
Preparation of silica-bonded N-propyltriethylenetetramine as a recyclable solid base catalyst for the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols)
Silica-bonded N-propyltriethylenetetramine was prepared via the reaction between 3-silicapropyl chloride and triethylenetetramine. This heterogeneous solid base was used as a catalyst for the synthesis of 4,4'-(arylmethylene)bis(1H-pyrazol-5-ols) by a one-pot condensation of aromatic aldehydes with 3-methyl-1-phenyl-5-pyrazolone in 72-93 % yields. The catalyst could be recycled several times without any additional treatment.