Synthesis of pyrimidine-annelated heterocycles: Regioselective synthesis of 1,3,6-trialkyl thieno[3,2-d]-pyrimidine-2,4-diones

Article abstract of DOI:10.1080/00397910008087036

Thermal [3,3] sigmatropic rearrangement of a number of 1,3-dimethyl-5-(prop-2-ynylthio)uracils (4a-j) afforded the title compounds 5a-j in 60-82% yields.