Electrocatalytic Multicomponent Transformation of Aldehyde, 5‐Amino‐3‐methyl‐1‐phenylpyrazole and Dimedone: An Efficient Protocol for Substituted Pyrazolo[3,4‐b]quinolines

Abstract

AbstractA convenient, rapid and electrochemical one‐pot protocol was developed successfully for the preparation of pyrazolo[3,4‐b]‐quinoline derivatives. The reaction is carried out in a 25 mL three neck flask equipped with graphite electrode as anode and iron electrode as cathode (electrode area of 1 cm2) with sodium bromide as supporting electrolyte at room temperature in ethanol. Fourteen pyrazolo‐[3,4‐b]‐quinoline derivatives were synthesized by use of various aldehyde (including aryl aldehydes and aliphatic aldehydes), dimedone and 5‐amino‐3‐methyl‐1‐phenylpyrazole as substrates in good yields (76–86 %) with a constant current of 30 mA after 0.14 F/mol of electricity passed. All aimed products were characterized by IR, 1H NMR and HRMS. Notably, the presented method features ecologically sound, simple experimental procedure and good yields.