Facile synthesis of 1H-imidazo[1,2-b]pyrazoles via a sequential one-pot synthetic approach.
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%.
AVIDIN Ltd., Alsó Kikötő sor 11, Szeged, H-6726, Hungary ; Department of Organic Chemistry, University of Szeged, Dóm tér 8, H-6720, Szeged, Hungary.
András
A
Demjén
AVIDIN Ltd., Alsó Kikötő sor 11, Szeged, H-6726, Hungary.
Márió
M
Gyuris
Department of Organic Chemistry, University of Szeged, Dóm tér 8, H-6720, Szeged, Hungary.
János
J
Wölfling
AVIDIN Ltd., Alsó Kikötő sor 11, Szeged, H-6726, Hungary ; AVICOR Ltd., Alsó Kikötő sor 11, Szeged, H-6726, Hungary.
László G
LG
Puskás
AVIDIN Ltd., Alsó Kikötő sor 11, Szeged, H-6726, Hungary.
Iván
I
Kanizsai
1H-imidazo[1,2-b]pyrazole; Groebke–Blackburn–Bienaymé reaction; N-heterocycles; isocyanide; multicomponent reaction