An environmentally benign, ionicliquid promoted multicomponent protocol to benzopyrano(2,3-d)pyrimidines and 4H-chromenes has been developed at roomtemperature. Results of the reaction depend on the nature of the nucleophile used in the reaction. Secondary amines result in the formation of benzopyrano(2,3-d)pyrimidines, whereas thiols give rise to 4H-chromenes under the same set of reaction conditions
MCRs for preparation of chromenopyridines under reflux conditions and chromenes at room temperature conditions from different salicylaldehydes, malononitrile and different thiols (mol ratio = 1:2:1) were established. Mechanistic investigation suggests that the MCRs undergo different pathways at different temperatures and catalyzed by different organic bases. The structure of chromenopyridine and chromene are confirmed by crystal X-ray crystallography. (C) 2014 Kai Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Greener construction of 4H-chromenes based dyes in deep eutectic solvent
作者:Najmedin Azizi、Mahboobe Mariami、Mahtab Edrisi
DOI:10.1016/j.dyepig.2013.09.007
日期:2014.1
environmentally-benign one-potreaction of salicylaldehyde and malononitrile with various nucleophiles, including indoles, thiols, secondary amines, cyanide and azide were efficiently achieved in choline chloride based deep eutectic solvent (DES). Products distribution of the current green protocol depend on the nature of the nucleophile used in the reaction. The one-potreaction of salicylaldehyde derivatives