for the following products
2-(2-Pyridon-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate | O-(1,2-Dihydro-2-oxo-1-pyridyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate | O-(2-Oxo-1(2H)pyridyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate | TPTU and O-(1,2-Dihydro-2-oxo-pyridyl]-N,N,N',N'-tetramethyluronium tetrafluoroborate
