UV light enabled methylation of quinoline-2-thione using dimethyl sulfoxide to give quinoline methyl sulfide.

Graphical abstract Highlights • Methylation of quinoline-2-thione under mild and environmentally friendly conditions. • DMSO as readily available source of methyl group. • Using UV light without metal- and dye-photocatalyst. Abstract An UV-light-induced S- methylation of quinoline-2-thione was completed by using dimethyl sulfoxide as methyl reagent. A series of quinoline methyl sulfides were prepared in moderate to good yields under environmentally friendly and mild conditions. [ABSTRACT FROM AUTHOR]