2-(2-Pyridon-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate125700-71-2100 % similar N,N,N',N'-Tetramethyl-O-(3,4-dihydro-4-oxo-1,2,3-benzotriazin-3-yl)uronium tetrafluoroborate125700-69-855 % similar 2-(2,5-Dioxopyrrolidin-1-yl)-1,1,3,3-tetramethylisouronium tetrafluoroborate105832-38-041 % similar O-(Benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate125700-67-636 % similar 2-(5-Norborene-2,3-dicarboximido)-1,1,3,3-tetramethyluronium tetrafluoroborate125700-73-435 % similar