Oxidation and nitrosation of 4-(3-alkylureido)-2, 2, 6, 6-tetramethylpiperidine-1-oxyls to 4-(3-alkyl-3-nitrosoureido)-2, 2, 6, 6-tetramethyl-1-oxopiperidinium salts
                                
                                    
                                        作者:V. D. Sen'、V. A. Golubev                                    
                                    
                                        DOI:10.1007/bf00698441
                                    
                                    
                                        日期:1993.3
                                    
                                    4-(3-Alkylureido)-2,2,6,6-tetramethylpiperidine-1-oxyls are rapidly oxidized by N2O4 or NOCl to 4-(3-alkylureido)-2,2,6,6-tetramethyl-1-oxopiperidinium nitrates and chlorides, which are then nitrosated to 4-(3-alkyl-3-nitrosoureido)-2,2,6,6-tetramethyl-1-oxopiperidinium salts. The perchlorates of the latter were prepared by an exchange reaction with HClO4. The nitrosation of alkylureidooxoammonium salts is the first example of chemical modification of oxoammonium derivatives in which the highly reactive >N+=O group is inert toward the reagent.