Swift and efficient synthesis of 4-phenylquinazolines: involvement of N-heterocyclic carbene in the key cyclization step.
An original route to 2-alkyamino-4-phenylquinazolines in three steps from simple (hetero)aromatic amines is reported here. The key step involves the intramolecular cyclization of benzoyl arylguanidines performed in [OMIm]Cl ionic liquid. The basic (hetero)aromatic guanidines deprotonate the imidazolium-based ionic liquid, thus triggering the cascade process ultimately leading to the intramolecular cyclization. This reaction is the first example of a Friedel-Crafts-type reaction in which an N-heterocyclic carbene is involved in the formation of the electrophilic intermediate.
Debray
Julien
J
Département Chimie Moléculaire, UMR 5250 & FR 2607, CNRS/Université de Grenoble, BP 53, 38041 Grenoble Cedex 9, France.
Lévêque
Jean-Marc
JM
Philouze
Christian
C
Draye
Micheline
M
Demeunynck
Martine
M
D003500:Cyclization; D019791:Guanidine / Q000138:chemical synthesis / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D011799:Quinazolines / Q000138:chemical synthesis* / Q000737:chemistry
D006571:Heterocyclic Compounds; D011799:Quinazolines; C030011:carbene; D019791:Guanidine; D008697:Methane