Benzimidazo[l,2-a]pyrazolo[l,5-c]quinazoline: a novel heterocyclic system

Heating of ethyl 3-[β-(benzimidazol-2-yl)hydrazine]-2-(polyfluorobenzoyl)acrylates in acetonitrile with potassium fluoride or triethylbenzylammonium chloride leads to derivatives of novel heterocyclic systems of benzimidazo[l,2-a]pyrazolo- [1,5-c]quinazoline.