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An Efficient Synthesis of 1,2,4‐Trisubstituted Imidazoles from Arylacetic Acids and N ‐Arylbenzamidines via Simultaneous C‐H and N‐H Bond Activation
Author(s) -
Pardeshi Sachin D.,
Vadagaonkar Kamlesh S.,
Lade Jatin J.,
Melone Lucio,
Chaskar Atul C.
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201700522
Subject(s) - nitromethane , chemistry , aldehyde , catalysis , imidazole , combinatorial chemistry , substrate (aquarium) , condensation reaction , michael reaction , ring (chemistry) , functional group , medicinal chemistry , organic chemistry , oceanography , polymer , geology
A convenient and effective FeCl 3 catalyzed one‐pot three component protocol for the synthesis of 1,2,4‐trisubstituted imidazoles from arylacetic acids , N ‐arylbenzamidines and nitromethane via simultaneous C−H and N−H bond activation has been developed. The reaction involves C−H activation of arylacetic acid to form aromatic aldehyde which on condensation with N ‐arylbenzamidine gives azadiene. Nitromethane on Michael addition with azadiene produces ring annulated intermediate which upon subsequent cyclization‐elimination sequence offers imidazole. The process utilizes readily available arylacetic acids and inexpensive catalyst. This user friendly protocol provided 1,2,4‐trisubstituted imidazoles in moderate to good yields with high functional group tolerance and ample substrate scope.