Abstract 6-[(Dimethylamino) methylene] amino-1, 3-dimethyluracil 1 undergoes formal [4+ 2] cycloaddition reactions with electron deficient olefins to give pyrido [2, 3-d] pyrimidines. With DMAD or azodicarboxylates Michael addition occurs leading to pyrrolo [3, 4-c] pyridines (X- ray analysis) and theophylline derivatives.