Transformations of methyl(phenyl)-substituted 1,4-dihydro-4-pyrimidinylidenemalononitriles under action of nitric acid
6-Phenyl-, 2-methyl-6-phenyl-, and 2,6-diphenyl-4-pyrimidinylidenemalononitrile in acetic acid react with HNO3 to form the corresponding 4-ethoxycarbonylpyrimidines in high yields after treatment of the intermediate product with ethanol. Under the same conditions 6-methyl-2-phenyl-4-pyrimidinylidenemalononitrile yields 6-methyl-5-nitro-4-ethoxycarbonylpyrimidine whereas 2-phenyl-4-pyrimidinylidenemalononitrile gives a mixture of 2-phenyl-4-ethoxycarbonyl- and 5-nitro-2-phenyl-4-ethoxycarbonylpyrimidine. 1999 KluwerAcademic/Plenum Publishers.