A Novel and Versatile Synthesis of 1-Alkyl-, 1-Aryl-, 1-(Alkylamino)-, or 1-Amido-Substituted and of 1,2,6-Trisubstituted Piperidines from Glutaraldehyde and Primary Amines or Monosubstituted Hydrazines

Article abstract of DOI:10.1021/jo00297a041

Various primary amines and 1-mono- and 1,1-disubstituted hydrazines were converted into the corresponding N-substituted piperidines in good to excellent yields via the products of double condensations with benzotriazole and glutaraldehyde.Reduction of the 2,6-bis(benzotriazolyl) N-substituted piperidines 4 and 7 with sodium borohydride in tetrahydrofuran afforded N-substituted piperidines.The benzotriazole moieties were also replaced by alkyl groups by reaction with Grignard reagents to produce 1,2,6-trisubstituted piperidines.