First synthesis of thiazepino[3,4‐a]isoquinolines, a facile new synthetic route to diazepino[3,4‐a]isoquinolines and assessment of their dopamine and σ receptor affinities

Heterocycles that bear the novel 5,6,14,14a-tetrahydro-8H-benzo[6,7][1,4] thiazepino[3,4-a]isoquinoline and the 5,6,14,14a-tetrahydro-8H-13l2-benzo [6,7][1,4]diazepino[3,4-a]isoquinoline frameworks were synthesized in a facile manner. These tetrahydroprotoberberine (THPB)-inspired scaffolds demonstrate selective affinity for the σ1R in contrast to the naturally occurring THPB congeners that show D1R and σ2R selectivity.