Benzoindolizine derivatives of N-acylphenothiazine. Synthesis and characterization.

A variety of unsaturated or partly and differentially saturated benzoindolizine derivatives of N-acylphenothiazine 1-3 has been efficiently synthesized by cyclocondensation of acetylenic or olefinic dipolarophiles with azomethineylide 4 derived from N-acetylisoquinolinium salt 5 flanking a phenothiazine unit.