Synfacts 2009(8): 0930-0930  
DOI: 10.1055/s-0029-1217491
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Benzopyrans with PEG-Based Dicationic Ionic Liquid

Contributor(s): Yasuhiro Uozumi, Takao Osako
H. Zhi, C. Lü, Q. Zhang, J. Luo*
Nanjing University of Science and Technology, P. R. of China
Further Information

Publication History

Publication Date:
23 July 2009 (online)

Significance

A PEG1000-based dicationic ionic liquid (PEG1000-DAIL) was prepared by the reaction of sodium imidazolide 1 with oligo(ethylene glycol) dichloride 2, followed by treatment with 1,3-sultone 4 in the presence of H2SO4 (eq. 1). PEG1000-DAIL promoted the three-component condensation of aromatic aldehydes, malononitrile or ethyl cyanoacetate, and 5,5-dimethyl-1,3-cyclohexanedione to afford the corresponding 5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyrans in 82-93% yield (17 examples, eq. 2).