Derivate der 1,3-Dimethyl-5-methylen-barbitursüure / Derivatives of 1,3-Dimethyl-5-methylenebarbituric Acid

Abstract

1,3-Dimethylbarbituric acid (1, R = Me) reacts with aqueous formaldehyde in the presence of pyridine to give 1,3-dimethyl-2,4,6-trioxo-5-pyridinomethyl-1,3-perhydrodiazin-5-ylpyridinium ylide (6) in good yield. From 6 and 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol- 2-ylidene (7), the zwitterionic imidazolium derivative 1,3-dimethyl-2,4,6-trioxo-5-(1,3-diisopropyl- 4,5-dimethylimidazoliomethyl)-1,3-perhydrodiazin-5-yl-imidazolium ylide (8) is obtained. Similarly, the phosphonium compound 1,3-dimethyl-2,4,6-trioxo-5-triphenylphosphoniomethyl-1,3- perhydrodiazin-5-y l-phosphonium ylide (9) is obtained from 6 and PPh3. The crystal structures of 8 and 9 are reported.