Synthetic route towards 1,2,3,4-tetrahydroquinoxaline/piperidine combined tricyclic ring system

The synthetic route toward novel tricyclic, nitrogen-containing system is disclosed. Three compounds possessing structural features of 1,2,3,4-tetrahydroquinoxaline and decahydropyrido[3,4-b]pyrazine are synthesized starting from readily available precursors in six or seven steps, which the last three four steps respectively diastereoselective. Key reaction include N-acylation, Hofmann rearrangement ring-closing Buchwald? Hartwig reaction. Compounds trans-8, cis-12 trans-12 order to prove that this novel, tricyclic can be functionalized with various groups. Synthetic significance heterocyclic lies possibility for orthogonal functionalization different amino groups, allowing fine tuning.