Synfacts 2009(1): 0024-0024  
DOI: 10.1055/s-0028-1087464
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Three-Component Synthesis of Substituted Chromenes

Contributor(s): Victor Snieckus, Johnathan Board
G. Shanthi, P. T. Perumal*
Central Leather Research Institute, Chennai, India
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Publikationsverlauf

Publikationsdatum:
18. Dezember 2008 (online)

Significance

Reported is the synthesis of 2-amino-3-cyano-4-allyl chromenes through the room-temperature three-component reaction of salicyl­aldehydes, malononitrile, and allyl bromides in the presence of sodium iodide and indium metal in water. A multi-stage mechanism is proposed, as shown, in which the malononitrile and aldehyde first undergo a Knoevenagel condensation, with subsequent phenolic OH attack to give the chromene. The resulting species undergoes reaction with an allylindium species to give the product. The reaction does not proceed well in organic solvents, or in the absence of sodium iodide.