Melting point apparatus

All the melting points were determined with a Cole-Parmer melting point apparatus (Cole-Parmer, Vernon Hills, Illinois, USA) while the thermometer was uncorrected. Optical rotation data were recorded on a KRUSS P8000 instrument (KRUSS, Karlsruhe, Germany). IR spectra were recorded on a Nicolet NEXUS-470 FTIR spectrometer (International Equipment Trading Ltd., Vernon Hills, Illinois, USA) with KBr pellets. ¹H NMR spectra were recorded with Bruker DPX300 (Bruker, Fallanden, Switzerland) and JEOL JNM-ECS400 (JEOL Ltd., Tokyo, Japan), while tetramethylsilane was used as an internal standard. Analytical thin-layer chromatography was carried out on silica gel 60 F254 plates, and spots were visualized with ultraviolet light. Elemental analysis was carried out with a Flash EA 1112 elemental analyzer (Thermo Finnigan, Bremen, Germany). Mass spectra were measured on a Bruker APEX IV spectrometer (Bruker, Fallanden, Switzerland).

Melting points were determined with a Cole-Parmer melting point apparatus (Cole-Parmer, Vernon Hills, IL, USA) (thermometer was uncorrected). IR spectra were recorded on a NEXUS-470 FTIR spectrometer (International Equipment Trading Ltd., Vernon Hills, IL, USA) with KBr pellets. ¹H NMR spectra were recorded with a Bruker DPX300 instrument (Bruker, Billerica, MA, USA) and tetramethylsilane was used as an internal standard. Analytical thin-layer chromatography (TLC) was carried out on precoated plates (silica gel 60 F254) and spots were visualized under ultraviolet light. Elemental analyses (C, H and N) were carried out with a Flash EA 1112 elemental analyzer (Thermo Finnigan, Bremen, Germany). Mass spectra were measured on a Bruker ESQUIRE-LC spectrometer (Bruker, Fallanden, Switzerland). The X-ray crystal diffraction (Bruker, Fallanden, Switzerland) data were collected with a Rigaku Saturn diffractometer at 294(2) K and the crystal structures were calculated using the SHELXL program package and refined by full-matrix least squares procedures at Nankai University (Tianjin, China).

All the melting points were determined with a Cole-Parmer melting point apparatus (Cole-Parmer, Vernon Hills, Illinois, USA) while the thermometer was uncorrected. IR spectra were recorded on a Nicolet NEXUS-470 FTIR spectrometer (International Equipment Trading Ltd., Vernon Hills, Illinois, USA) with KBr pellets. ¹H NMR spectra were recorded with a Bruker DPX300 instrument (Bruker, Fallanden, Switzerland), while tetramethylsilane was used as an internal standard. Analytical thin-layer chromatography (TLC) was carried out on silica gel 60 F254 plates, and spots were visualized with ultraviolet (UV) light. Elemental analyses (C, H and N) were carried out with a Flash EA 1112 elemantal analyzer (Thermo Finnigan, Bremen, Germany). Mass spectra were measured on a Bruker ESQUIRE-LC spectrometer (Bruker, Fallanden, Switzerland). The X-ray crystal diffraction data were collected with a Rigaku Saturn diffractometer (Japan) at 294(2) K and the crystal structures were calculated using the SHELXL program package and refined by full-matrix least squares procedures at Nankai University.