Sp 930 d

All reagents and solvents were obtained commercially unless otherwise mentioned. The solvents we used were dried by conventional methods. All reactions were performed with nitrogen protected. The ¹H and ¹³C NMR spectra were recorded on a Mercury 400 MHz NMR, Varian, Palo Alto, CA, USA and 600 MHz NMR. (CDCl₃ and DMSO-d₆ were used as the solvent and TMS was the internal standard). MS spectra were measured on Bruker Daltonics Data Analysis 3.4 Mass Spectrometer, Bruker, Karlsruhe, Germany and Thermo LTQ Orbitrap-XL Mass Spectrometer (Thermo Scientific, Waltham, MA, USA). HSGF 254 high-efficiency thin-layer chromatography silica gel plates were bought from Huiyou Development Co., Yantai, Shangdong, China. Ltd. HSGF 254 thin-layer silica gel (300 mesh to 400 mesh) was bought from Ocean Chemical Plant (Qingdao, Shangdong, China). Analytic HPLC analysis was performed on a YOUNG LIN instrument with a Luna C-18(2) 100A 4.6 × 250 mm 5 μm column, SP930D solvent delivery pump, UV730D UV/VIS dual absorbance detector. HPLC analysis showed that the purity of all the final products were >95%. The column was eluted with acetonitrile at a flow rate of 0.5 mL/min.