H. Kumar and A. Parmar, “Ultrasound Promoted ZrCl4 Catalyzed Rapid Synthesis of Substituted 1,2,3,4-Tetrahydropyrimidine-2-Ones in Solvent or Dry Media,” Ultrasonics Sonochemistry, Vol. 15, No. 2, 2008, pp. 129-132. http://dx.doi.org/10.1016/j.ultsonch.2007.02.003

has been cited by the following article:

• TITLE: Phase Transfer Catalysis Improved Synthesis of 3,4-Dihydropyrimidinones

  AUTHORS: Hela Slimi, Khemaïs Saïd, Younes Moussaoui, Ridha Ben Salem

  KEYWORDS: Multicomponent Reaction; Biginelli Reaction; 3, 4-Dihydropyrimidinones; Phase-Transfer Catalysis; Quaternary Ammonium Salts

  JOURNAL NAME: International Journal of Organic Chemistry, Vol.3 No.3A, November 28, 2013

  ABSTRACT: Various 3,4-dihydropyrimidinones can be prepared via Biginelli reaction in aqueous media by using quaternary ammonium salts of different alkyl groups (C4 and C8) and anions (Cl-and Br-) as catalysts. The use of quaternary ammonium salts along with longer alkyl chains increases the yield of the Biginelli reaction; however, bromide ammonium salts are less active than the chloride ones.