Thermal Reactions of 6-Methyl-5-[(substituted hydrazono)methyl]- 2,4(1<i>H</i>,3<i>H</i>)-pyrimidinediones with Electron-Deficient Olefins and Acetylene
The thermal reactions of some 6-methyl-5-[(substituted hydrazino)methyl]-2,4(1H,3H)-pyrimidinediones (1) were investigated. The 1,5-hydrogen shift in 1 gave 5,6-dihydro-5,6-bis(methylene)-2,4(1H,3H)-pyrimidinedione intermediates, while the 1,2-hydrogen shift in 1 gave azomethine imine intermediates. These reaction profiles depend on the substituents of hydrazone moieties.