Synthetic applications of 2-aryl-4-piperidones. IX: Synthesis of pyrido [1',2':1,2]imidazo [4,5-a]-quinolizidin-2-one

The synthesis of the new heterocyclic compound pyrido[1',2':1,2]imidazo-[4,5-a]quinolizidin-2-one (1), an aza analog of indolo[2,3-a]quinolizidin-2-one, has been effected in four steps from an appropriate 2-aryl-4-piperidone (2), including closure of ring C as the key step