Convenient Synthesis of 5-Trifluoroacetylated Imidazoles by Ring Transformation of Mesoionic 1,3-Oxazolium-5-olates.
作者:Masami KAWASE、Setsuo SAITO
DOI:10.1248/cpb.48.410
日期:——
Mesoionic 4-trifluoroacetyl-1, 3-oxazolium-5-olates (1), obtained from the reaction of N-acyl-N-alkylglycines (2) with trifluoroacetic anhydride, react with amidines to give 5-trifluoroacetylimidazoles (3) in moderate yield. The novel ring trandformations of 1 into 3 occur via an initial attack of amidines on the C-2 position of the ring.
A novel ring transformation of mesoionic 1,3-oxazolium-5-olates into 5-trifluoroacetylated and 5-perfluoroacylated imidazoles by reaction with amidines
作者:Masami Kawase
DOI:10.1039/c39940002101
日期:——
Treatment of mesoionic 1,3-oxazolium-5-olates with amidines causes a novel ring transformation affording 5-trifluoroacetyl- and 5-perfluoroacyl-imidazoles in moderate yields.
An Efficient Synthesis of 4-Trifluoromethylated and 4-Perfluoroalkylated Imidazoles from Mesoionic 1,3-Oxazolium-5-olates
作者:Masami Kawase、Setsuo Saito、Teruo Kurihara
DOI:10.3987/com-95-7110
日期:——
4-Trifluoromethyl- and 4-perfluoroalkylimidazoles (4) were conveniently synthesized from mesoionic 4-trifluoroacetyl- or 4-perfluoroacyl-1,3-oxazolium-5-olate (1) via 2-imidazolines (3), which were formed through the regioselective attack of ammonia on the C(2) position of 1.
Kawase Masami, J. Chem. Soc. Chem. Commun, (1994) N 18, S 2101-2102
作者:Kawase Masami
DOI:——
日期:——
Convenient Synthesis of 4-Trifluoromethyl-Substituted Imidazole Derivatives.
作者:Masami KAWASE、Setsuo SAITO、Teruo KURIHARA
DOI:10.1248/cpb.49.461
日期:——
Mesoionic 4-trifluoroacetyl-1, 3-oxazolium-5-olates (1), obtained from the reaction of N-acyl-N-alkylglycines (2) with trifluoroacetic anhydride, react with ammonia to give 4-trifluoromethyl-3, 4-dihydroimidazoles (3) in high yields. Dehydration of 3 gives 4-trifluoromethylimidazoles (4) in high yields. The novel ring transformation of 1 into 3 occurs via a regioselective attack of ammonia on the C-2 position of the ring.