Modification of Pyrrolo[2,1- a ]isoquinolines and Pyrrolo[1,2- a ]quinolines with Ammonium Acetate and Dimethyl Sulfoxide via Methylthiomethylation.

An efficient methylthiomethylation of pyrroloisoquinolines and pyrroloquinolines has been reached by the use of ammonium acetate and dimethyl sulfoxide. Methylthiomethylated heterocycles can be obtained in moderate to good yields in most cases, while trace amounts to good yields of methylene-bridged products can be observed. Choice of DMSO activator and its amount have a great influence on the chemoselectivity of this process. It is worth noting that this process can also be scalable. Another feature of this process is that the product can be transformed to sulfone and sulfoxide easily.