Facile and rapid synthesis of (۲Z)-(۲-oxo-۱,۲-dihydro-۳H-indol-۳-ylidene)(۱H-tetrazol-۵-yl)ethanenitrile via a multi-component domino knoevenagel condensation/۱,۳ dipolar cycloaddition reaction catalyzed by reusable ZrP۲O۷ NPs

چکیده مقاله

Herein, we would like to report a novel and one-pot process for synthesis of (2Z)-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)(1H-tetrazol-5-yl)ethanenitrile via a multi-component domino knoevenagel condensation/1,3 dipolar cycloaddition reaction of isatine, malononitrile and sodium azide in DMF with ZrP2O7 NPs as an effective and re-useable heterogeneous catalyst has been reported (Scheme 1). The best evidence for the formation of presumably less sterically hindered (Z)-configuration is the appearance of a deshielded signal for H-4 of the indole ring system (9.07 ppm) in the 1H NMR spectrum of compound 2, likely resulting from the anisotropic effect of the nitrile group.