Organic Reactions in Ionic Liquids: An Efficient Method for Selective S‐Alkylation of 2‐Mercaptobenzothia(xa)zole with Alkyl Halides

Ionic liquids based on 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BmimPF6) and 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BmimBF4) are used as reusable reaction medium in the selective S‐alkylation of 2‐mercaptobenzothia(xa)zole with alkyl halides in the presence of potassium carbonate. This procedure is convenient, efficient, and generally gives rise to the S‐alkylated product exclusively.