Thienoquinolizidinones. Synthesis and rearrangement into new piperidino[1,2-a][1,3] or [1,4]diazepinones fused to a thiophene ring

A convenient route to thienoquinolizidinones is described starting from ethyl pipecolinate and suitable halogenomethylthiophenes or 3-chloromethylbenzothiophene. The Schmidt reaction and the Beckmann rearrangement of oximes of these ketones led to piperidino1,2-a]1,3] or 1,4]diarepines fused to a thiophene ring.