[bmim(SO3H)][OTf]/[bmim][X] and Zn(NTf2)(2)/[bmiml[X] (X = PF6 and BF4); efficient catalytic systems for the synthesis of tetrahydropyrimidin-ones (-thiones) via the Biginelli reaction

摘要

A facile, high yielding, and simple method for the synthesis of a library of dihydropyrimidinones (and-thiones) via the one-pot Biginelli reaction of aldehydes is reported. The method employs the Bronsted acidic IL [bmim(SO3H][OTf] or Zn(NTf2)(2) as catalyst along with the readily available imidazolium-ILs as solvent, and exhibits good potential for the recycling and reuse of the IL solvent. (C) 2016 Elsevier Ltd. All rights reserved.