Direct Arylation of Imidazo[1,2-b]pyridazines: Microwave-Assisted One-Pot Suzuki Coupling/Pd-Catalysed Arylation

Direct intermolecular C–H arylation of 6‐chloroimidazo[1,2‐b]pyridazine in its 3‐position was achieved, and the tolerance to reaction conditions in the presence of chloro groups was investigated. Various 3‐(hetero)arylimidazo[1,2‐b]pyridazines were synthesized in good to excellent yields. This methodology was successfully applied to the synthesis of 3,6‐di‐ and 2,3,6‐trisubstituted imidazo[1,2‐b]pyridazines by a microwave‐assisted, one‐pot, two‐step Suzuki cross‐coupling/palladium‐catalysed arylation process. Direct intermolecular C–H arylation of 6‐chloroimidazo[1,2‐b]pyridazine in its 3‐position was achieved, and various 3‐(hetero)arylimidazo[1,2‐b]pyridazines were synthesized in good yields. This methodology was applied to the synthesis of 3,6‐di‐ and 2,3,6‐trisubstituted imidazo[1,2‐b]pyridazines by a microwave‐assisted, one‐pot, two‐step Suzuki cross‐coupling/Pd‐catalysed arylation process.