Convenient synthesis of 4-trifluoromethyl-substituted imidazole derivatives.
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.
Kawase
M
M
Faculty of Pharmaceutical Sciences Josai University, Sakado, Saitama, Japan. kawasema@josai.ac.jp
Saito
S
S
Kurihara
T
T
D000085:Acetates; D007093:Imidazoles / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy
D000085:Acetates; D007093:Imidazoles; D007202:Indicators and Reagents; C018824:ammonium acetate