Brönsted acidic ionic liquid as an efficient catalyst for chemoselective synthesis of 1,1-diacetates under solvent-free conditions

We introduce a simple and efficient procedure for preparation of (1-H-3-methyl-imidazolium hydrogen sulfate) as a Brönsted acidic ionic liquid using 1-methylimidazole in the presence of concentrated sulfuric acid. Further, this Brönsted acidic room temperature ionic liquid has been employed as a catalyst for the synthesis of 1,1-diacetates from aldehydes under mild and solvent-free conditions at room temperature.