Chemistry of benzo[b]furan. V.. Synthesis of substituted thia‐analogs and oxa‐analogs of dihydrorutecarpine and evodiamine

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 = CH3) 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‐methyl derivatives of thia‐analogs of dihydrorutecarpine and evodiamine (2c‐2i) and oxa‐analogs of dihydrorutecarpine and evodiamine (1a‐1g) were similarly prepared.