1,3-Disulfonic acid imidazolium hydrogen sulfate as an efficient and reusable ionic liquid catalyst for the N-Boc protection of amines

1,3-Disulfonic acid imidazolium hydrogen sulfate is easily prepared and used as an efficient and recyclable ionic liquid for the N-Boc protection of amines at room temperature and neat conditions. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times without loss of activity. (C) 2012 Elsevier B.V. All rights reserved.