M. Guillaume, Jef Cuypers, J. Dingenen
Nov 16, 2007
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Influential Citations
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Journal
Organic Process Research & Development
Abstract
We describe in this paper the synthesis of compound 1 (R116301), which was developed to prepare pilot scale quantities (20–50 kg) of drug substance. The synthesis involves the sBuLi deprotonation of Boc-protected piperidone acetal 2, followed by benzaldehyde addition and ring closure to cyclic carbamate 4. Piperidine acetal 5 is resolved with Brown’s acid and acylated. The ketone obtained after piperidine acetal deprotection undergoes reductive amination with N-benzyl piperazine, the most critical step in the synthesis. After debenzylation, final coupling and salt formation, compound 1 is obtained over 10 steps with 4% overall yield.