Ring-chain isomerism of ethyl 7-polyfluoroalkyl-7-hydroxy-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylates
                                
                                    
                                        作者:Marina V. Pryadeina、Yanina V. Burgart、Viktor I. Saloutin、Oleg N. Chupakhin                                    
                                    
                                        DOI:10.1016/j.mencom.2008.09.017
                                    
                                    
                                        日期:2008.9
                                    
                                    Cyclisation of ethyl 2-ethoxymethylidene-3-oxo-3-polyfluoroalkylpropionates with 3-amino-1H-[1,2,4]triazole gives ethyl 7-polyfluoroalkyl-7-hydroxy-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylates that are subject to ring-chain isomerisation in solution, depending on the solvent and the length of the polyfluoroalkyl substituent, to yield ethyl 3-polyfluoroalkyl-3-oxo2-([1,2,4]triazol-3-yl)aminomethylidene}propionates via heterocyclic ring opening at the C(7)-N(8) bond.