Synthesis of 4-Hydroxy-6-methyl-[(1-phenylimino)ethyl]-2 H-pyran-2- one Derivatives Catalyzed by Ionic Liquid [BMIM-HSO 3]HSO 4 under Ultrasound
Li Daqing, Zang Hongjun, Wu Changchun, Lu Bo, Cheng Bowen
Chin. J. Org. Chem. . 2012, (11): 2193 -2197 .  DOI: 10.6023/cjoc201204020