Synthesis of fluorinated isoxazoles using SelectfluorTM : preparation and characterization of 4-fluoroisoxazole, 4,4,5-trifluoroisoxazoline and 4,4-difluoro-5-hydroxyisoxazoline systems from one-pot and multi-step processes.

摘要

3,5-Disubstituted 4-fluoroisoxazole, 4,4,5-trifluoroisoxazoline and 4,4-difluoro-5-hydroxyisoxazoline products were obtained from reaction of the corresponding isoxazoles with SelectfluorTM depending upon the reaction conditions. Although the fluorinations proceeded using conventional heating, microwave (μW) irradiation considerably shortened reaction times and enabled a high yielding one-pot cascade fluorination-cyclization from simple diketone substrates. In addition, a related 4-fluoroisoxazole-3-carboxyamide derivative was synthesized.