Facile synthesis of 1H-imidazo[1,2-b]pyrazoles via a sequential one-pot synthetic approach

[vc_row][vc_column][vc_message]Demjén A, Gyuris M, Wölfling J, Puskás LG, Kanizsai I.[/vc_message][vc_column_text]


5-Aminopyrazole-4-carbonitrile and ethyl 5-aminopyrazole-4-carboxylate, as potential trifunctional building blocks are introduced in a facile, chemo- and regioselective multicomponent assembly of imidazo[1,2-b]pyrazoles via the Groebke–Blackburn–Bienaymé reaction (GBB reaction). Besides the synthetic elaboration of a green-compatible isocyanide-based access in three-component mode, we describe an operationally simple, one-pot two-step GBB protocol for the rapid construction of a 46 membered imidazo[1,2-b]pyrazole library with yields up to 83%.