Regioselective Preparation of 1-(Bromomethyl)-5H-thiazolo[3,2-a]quinazolin-5-ones and Analogous 5H-Thieno[3,2-e]thiazolo[3,2-a]pyrimidin-5-ones from Fused 2-(Alkenylthio)pyrimidin-4-ones - Wippich, Petra; Gütschow, Michael; Leistner, Siegfried (Synthesis, 2000)