Abstract Cycloaddition of 3, 4-dihydrobenzo [b] thieno [2, 3-c] pyridine (6) with the sulfinamide anhydride 9 (R= H) afforded the thia-analog of dihydrorutecarpine (2a). Condensation of the imine 6 with the sulfinamide anhydride 9 (R= CH 3) gave the thia- analog of evodiamine (2b). Starting from 1-methyl-3, 4-dihydrobenzo [b] thieno [2, 3-c] pyridine (12) and 1-methyl-3, 4-dihydrobenzo [b] furo [2, 3-c] pyridine (14), a series of 3- ...