Microwave-enhanced synthesis of 2,3,6-trisubstituted pyridazines: application to four-step synthesis of gabazine (SR-95531).

Microwave-enhanced, highly efficient protocols for the synthesis of synthetically and biologically important 2,3,6-trisubstituted pyridazine architectures have been developed by sequential amination/Suzuki coupling/alkylation reactions. This powerful strategy is an economical and highly chemoselective protocol for the synthesis of diversified pyridazines. The total synthesis of gabazine (SR-95531) has been achieved using a versatile strategy in four steps and 73% overall yield.