New application of Pictet-Spengler reaction leading to the synthesis of an unusual seven-membered heterocyclic ring system.
A novel strategy for the Pictet-Spengler reaction is reported. Our strategy involves reaction of arylamines, linked to the N-1 of disubstituted imidazoles, with aldehydes in the presence of p-TsOH. The iminium ion generated in situ undergoes C-C bond formation with the C-5 of the imidazoles to furnish triazabenzoazulenes as a novel heterosystem. Our strategy differs from conventional Pictet-Spengler reaction since the latter utilizes only aliphatic amines in which the amine functionality is linked to a C instead of N of the activated aromatic moiety.
Kundu
Bijoy
B
Division of Medicinal Chemistry, Central Drug Research Institute, Lucknow 226001, India. bijoy_kundu@yahoo.com
Sawant
Devesh
D
Partani
Pankaj
P
Kesarwani
Amit P
AP