Thiophen als Strukturelement physiologisch aktiver Substanzen, 8. Mitt. 1H,5H-Imidazo[1,2-a]thieno[3,4-d]pyrimidin-2(3H)-one

Thiophene as a Structural Element of Physiologically Active Compounds, VIII: 1H,5H-Imidazo[1,2-a]thieno[3,4-d]pyrimidin-2(3H)-ones The tricyclic title compound 1 can be synthesized in one step from the thiophene compounds 13 or 17 by base induced twofold ring closure.