Application of biphasic reaction procedure using ferric chloride dissolved in an imidazolium salt and benzotrifluoride (FeIm-BTF procedure) to aza-Prins cyclization reaction

✍ Scribed by Eietsu Hasegawa; Nohara Hiroi; Chika Osawa; Eiji Tayama; Hajime Iwamoto

• Book ID: 104098431
• Publisher: Elsevier Science
• Year: 2010
• Tongue: French
• Weight: 292 KB
• Volume: 51
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2010.10.018

✦ Synopsis

Aza-Prins cyclization reaction of N-tosyl-3-butenylamine with aliphatic and aromatic aldehydes was performed using a combination of FeCl 3 and 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF 6 ) or 1-butyl-3-methylimidazolium tetrachloroferrate (BmimFeCl 4 ) in benzotrifluoride (BTF). The desired Ntosyl-4-chloro-2-substituted piperidines were obtained from aliphatic aldehydes in comparable yields to those for the previously reported reactions in which FeCl 3 was used in CH 2 Cl 2 . On the other hand, significant progress for the piperidine synthesis from aromatic aldehydes has been achieved, particularly when BmimFeCl 4 was used with FeCl 3 in BTF.