Sulfated polyborate catalysed efficient synthesis of 2-amino-4-(subs./het)aryl-5-oxo-4,5-dihydropyrano[3,2-c]chromene/quinolone-3-carbonitrilesSanket Kadam, Yukta Sansare, and Ganesh Chaturbhuj Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, India
E-mail: gu.chaturbhuj@gmail.com Received: 2 April 2025 Accepted: 20 January 2026 Abstract: This study describes the synthesis of 2-amino-4-(substituted/hetero)aryl-5-oxo-4,5-dihydropyrano[3,2-c]chromene/quinolone-3-carbonitriles, with improved yields obtained in DMF at 90 °C, using sulfated polyborate as a catalyst. The catalyst provides excellent results and shows good functional group tolerance, with yields ranging from 82 to 93% for various aromatic and heteroaromatic (substituted/hetero)arylidene malononitriles. The key advantages of this method include shorter reaction times and higher product yields. This optimized reaction condition enabled the synthesis of valuable heterocyclic compounds from readily available reactants. In total, 32 substrates were successfully synthesized under optimized reaction conditions. The synthesized compounds were characterized using FTIR, 1H NMR, 13C{1H} NMR, high-resolution mass spectrometry, and elemental analysis. Graphical abstractSulfated Polyborate was used as an acid catalyst in organic transformations. It efficiently catalyzed the 4-hydroxycoumarin, chloro substituted 4-hydroxycoumarin, 4-hydroxy-1-methylquinolin-2(1H)-one, bromo substituted 4-hydroxy-1-methylquinolin-2(1H)-one with (subs./het)arylidene malononitriles in DMF as a solvent producing 2-amino-4-(subs./het)aryl-5-oxo-4,5-dihydropyrano[3,2-c]chromene/ quinolone-3-carbonitriles with excellent yield.  Keywords: Sulfated polyborate; (subs./het)arylidene malononitriles; 4,5-dihydropyrano[3,2-c]chromene/quinolone Full paper is available at www.springerlink.com. DOI: 10.1007/s11696-026-04690-z
Chemical Papers 80 (4) 4275–4281 (2026) |
Monday, May 18, 2026 
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