title: L-Proline as an efficient and reusable promoter for the synthesis of coumarins in ionic liquid.
abstract: The effect of L-proline as a promoter on the condensation reaction of salicylaldehyde or its derivatives with ethyl acetoacetate in neutral ionic liquid [emim]BF4 was studied. All reactions were carried out under mild reaction conditions and achieved high yields. Moreover, the ionic liquid containing L-proline could be recycled and reused for several times without noticeably decreasing in productivity. The results show that the L-proline-[emim]BF4 system has a potential in contribution to the development of environmentally friendly and inexpensive processes in organic syntheses.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xiu-hong
authors.initials: XH
authors.lastname: Liu
authors.forename: Ji-cai
authors.initials: JC
authors.lastname: Fan
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhi-cai
authors.initials: ZC
authors.lastname: Shang
mesh_terms: D003374:Coumarins / Q000138:chemical synthesis*; D052578:Ionic Liquids / Q000737:chemistry*; D011392:Proline / Q000737:chemistry*
chemical_list: D003374:Coumarins; D052578:Ionic Liquids; D011392:Proline