A series of pyrazole-4-carboxylates have been synthesised using indium bromide catalyst and the cyclisation of respective 3-substituted-isoquinolinylhydrazines 1 into their corresponding ethyl-2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutanoates 3 in ethanol solvent under ultrasonic irradiation at 90 °C for 30 min. The regio-selective cyclisation products were efficiently provided by indium bromide catalyst and are confirmed by nuclear Overhauser effect spectroscopy–nuclear magnetic resonance (NOESY–NMR) studies.

Indium bromide catalyst efficiently synthesises regio-selective pyrazole-4-carboxylates using ultrasound-assisted cyclisation of 3-substituted-isoquinolinylhydrazines in ethanol solvent.

Research on Chemical Intermediates

Indium bromide catalysed, ultrasound-assisted, regio-selective synthesis of ethyl-5-(trifluoromethyl)-1-(3-substituted-isoquinolin-1-yl)-1H-pyrazole-4-carboxylates

Paper

Indium bromide catalysed, ultrasound-assisted, regio-selective synthesis of ethyl-5-(trifluoromethyl)-1-(3-substituted-isoquinolin-1-yl)-1H-pyrazole-4-carboxylates

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