Heterocyclization of 2-aryl-3-arylamino-4,4,4-trifluoro-2-butenenitrile hydrates to 3-aryl-2-trifluoromethyl-4-quinolones and to 4-N-methylamino-3H-pyrazole-3-spiro-2'-(3'-aryl-3'-trifluoromethyl)axiranes

Article abstract of DOI:10.1016/0022-1139(94)03201-A

2-Aryl-3-arylamino-4,4,4-trifluoro-2-butenitriles were obtained as hydrates from 3-oxo-2-aryl-4,4,4-trifluorobutyronitriles and anilines and their structure and heterocyclizations studied.Cyclization with polyphosphoric acid gave poor yields of 3-aryl-2-trifluoromethyl-4-quinolones, but they underwent an interesting cyclization with diazomethane to give a 25percent-40percent yield of 4-N-methylamino-3H-pyrazole-3-spiro-2'-(3'-aryl-3'-trifluoromethyl)oxiranes.However, the related reaction with diazoethane yielded anly aryl(arylhydrazono)acetonitriles and other fragmentation products. - Keywords: Heterocyclizations; Fluorinated oxiranes; NMR spectroscopy; IR spectroscopy; UV spectrophotometry