Montmorillonite-KSF mediated one step synthesis of pyranochromene derivatives

• Published in: Journal of molecular structure Vol. 1171; pp. 747 - 754
• Main Authors: Subbareddy, Chitreddy V., Subashini, Radhakrishnan, Sumathi, Shanmugam
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2018
• Subjects: 4-Hydroxycoumarin; Aromatic aldehydes; Heterogeneous catalyst; Montmorillonite KSF (MKSF); Multicomponent reaction; Pyrano[3,2-c]chromene; Montmorillonite KSF (MKSF); Heterogeneous catalyst; Multicomponent reaction; Pyrano[3,2-c]chromene; Aromatic aldehydes; 4-Hydroxycoumarin
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2018.06.052

One-pot three-component reaction of substituted aromatic aldehydes, 2-cyanoacetamide and 4-hydroxycoumarin in the presence of Montmorillonite-KSF (MKSF) in ethanol results in the formation of pyrano[3,2-c]chromene-3-carboxylates (5a-m) has been described. The reaction was tested in different alcohols, afforded pyrano [3,2-c] chromene-3-carboxylates (5a-m) of the corresponding alcohols in good yield. The mechanism reveals that the alcohol (as solvent) plays a major role in the inter conversion of amide to the corresponding esters with Montmorillonite KSF (M-KSF) as a catalyst. Excellent yields, inexpensive and readily available substrates, environmentally benign reaction condition, shorter reaction time, and easy workup are the major advantageous features of this protocol. [Display omitted] •Montmorillonite-KSF is an effective heterogeneous catalyst.•Easy to handle and simple reaction procedure.•Cost effective and high yields were observed in shorter reaction time.•Reusability of catalyst.