文摘
The synthesis of cis-N-benzyl-3-methylamino-4-methylpiperidine(5) via hydroboration of tetrahydropyridine 3 followed byoxidation and reductive amination was optimized and scaledup to produce 10-kg quantities of product. Three routes to 3were identified, and the reduction of pyridinium salt 7 wasselected as the most preferable to run on-scale. The hydroboration and oxidative workup were carefully studied to optimizethroughput on that transformation, as was the reductiveamination.