P. Schneiders, J. Heinze and H. Baumgartel, “Synthesis of 4,4’,5,5’-Tetrasubstituted Di-2-imidazolyl Derivatives, Starting Materials for the Synthesis of 1,4,5,8-Tetraazafulvalenes,” Chemische Berichte, Vol. 106, No. 7, 1973, pp. 2415-2417.
http://dx.doi.org/10.1002/cber.19731060739

has been cited by the following article:

• TITLE: Solvent Free One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Catalyzed by Secondary Amine Based Ionic Liquid and Defective Keggin Heteropoly Acid

  AUTHORS: Pranab Jyoti Das, Jupitara Das, Munni Ghosh, Sabera Sultana

  KEYWORDS: Ionic Liquids; Keggin Heteropolyacid; Microwave; Tetrasubstituted Imidazole; Solvent Free Synthesis; Multicomponent Reaction

  JOURNAL NAME: Green and Sustainable Chemistry, Vol.3 No.4A, November 22, 2013

  ABSTRACT: Secondary amine based ionic liquid and defective Keggin type heteropoly acid (HPA) are separately used for efficient one-pot four-component synthesis of 1,2,4,5-tetrasubstituted imidazoles assisted by microwave (MW). Eco-friendly solvent free procedure, short reaction time, high yield of products and reusability of catalysts are important features of the synthesis. A comparative study on the efficiency of the two catalysts is reported. This work further demonstrates the alternate use of urea, instead of often used ammonium acetate, as source of nitrogen.