Synthesis of Benzothiazoles through Copper-Catalyzed One-Pot Three-Component Reactions with Use of Sodium Hydrosulfide as a Sulfur Surrogate

Abstract

Copper-catalyzed one-pot three-component reactions of 2-iodoanilines, aldehydes, and NaSH.n?H2O afford benzothiazoles in good yields. When CuCl was employed as a catalyst in the absence of a ligand, a variety of aromatic aldehydes and substituted 2-iodoanilines reacted with NaSH.n?H2O to produce the corresponding 2-arylbenzothiazoles in 7098?% yields. The copper catalyst plays a key role in CS bond formation between NaSH.n?H2O and the aryl iodide that was formed from the condensation of 2-iodoaniline and aldehyde. It was found that NaSH.n?H2O functions as a sulfur surrogate and oxidant in the formation of benzothiazole.