ACETONE 4,4-DIMETHYL-5-OXO-2-PYRAZOLIN-3-YLHYDRAZONE

The title compound, C8H14N4O. exhibits an overall molecular coplanarit y and trigonal planar geometry of all four N atoms, suggesting resonan ce interaction extending over eight contiguous atoms. Strong hydrogen bonding between hydrazidic-N donor and carbonyl-O acceptor atoms resul ts in an almost-planar octagonal bridge between two molecules. These d imers are interconnected through a second octagonal bridge of weaker h ydrogen bonds between side-chain hydrazine-N donor and ring-N acceptor atoms, leading to an almost-flat linear polymeric structure. The acet one-hydrazone N atom does not participate in hydrogen bonding. From th e structure of the title compound, the unequivocal identification of 4 ,4-dimethyl-5-oxo-2-pyrazolin-3-ylhydrazine, an unexpected byproduct o f the reaction of 4,4-dimethylpyrazolidine-3,5-dione with hydrazine, w as made.