Insertion Reaction of 2-Halo-N-allylanilines with K2S Involving Trisulfur Radical Anion: Synthesis of Benzothiazole Derivatives under Transition-Metal-Free Conditions

A synthesis of benzothiazole derivatives through the reaction of 2-halo-N-allylanilines with K2S in DMF is developed. The trisulfur radical anion S-3(center dot-), which is generated in situ from K2(S) in DMF, initiates the reaction without transition-metal catalysis or other additives. In addition, two C-S bonds are formed and heteroaromatization of benzothiazole is triggered by radical cyclization and H-shift.

Automated summary

A new method for the synthesis of benzothiazole derivatives through the reaction of 2-halo-N-allylanilines with K2S in DMF has been developed. This reaction is initiated by the trisulfur radical anion S-3(center dot-), generated in situ from K2(S) in DMF, without the need for transition-metal catalysis or other additives. In addition to forming two C-S bonds, the heteroaromatization of benzothiazole is triggered by radical cyclization and H-shift.