Ring-expansion Reaction of N-Boc-4-piperidone

The Chemical Development Drug Evaluation branch of Johnson Johnson Pharmaceutical Research Development LLC in Raritan, NJ, USA, investigated the ring-expansion reaction of N-Boc-4-piperidone with ethyl diazoacetate in a microreactor system as an example of processing hazardous substances [42]. 

Inspired by the Johnson Johnson research, this procedure was developed further and is used by Sigma-Aldrich for the catalog production of N-Boc-hexahydro-1 H-azepin-4-one. The microreaction is followed by base-induced decarboxylation performed in a conventional batch reactor [43]. 

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