Synthesis of 1H-isoindol-3-amine derivatives by iodine-mediated cyclization of 2-vinylbenzamidine derivatives

It has been found that the reaction of 2-vinylbenzamidine derivatives, prepared by reacting 2-vinylbenzonitriles with lithium cyclic secondary amides, with iodine in the presence of sodium hydrogen carbonate in acetonitrile resulted in the formation of the corresponding l-iodomethyl-1H-isoindole-3-amine derivatives in reasonable overall yields based on the starting 2-vinylbenzonitriles. We have also found that transformation of these 1-iodomethyl derivatives into 1-sulfenylmethyl derivatives could be achieved in good yields on treatment with various sodium thiolates.