An improved synthesis of N-aryl and N-heteroaryl substituted homopiperazines-from conventional thermal conditions to scaling-up using microwave heating

An efficient Pd(0)-catalyzed Buchwald-Hartwig protocol for the facile preparation of N-aryl and N-heteroaryl substituted homopiperazines is described. The syntheses proceeded with aryl- and heteroaryl halides in high yields using X-Phos as best ligand. The C-N coupling products were prepared both under conventional as well as microwave heating conditions and examples for microwave-assisted upscaling are included in this study.