by spectroscopic data analysis. The NMR spectra were recorded on a
Bruker DRX500 or DRX600 NMR spectrophotometer (Bruker Biospin GmbH,
Ettlingen, Germany); chemical shifts (δ) are expressed in ppm, J values are given in Hz, and deuterated dimethyl sulfoxide
(DMSO)-d6 or CDCl3 was used
as solvent. The IR spectra were recorded on a Fourier transform infrared
(FT-IR) Avatar 360 spectrophotometer (Thermo Nicolet Corp., Madison
WI) using the KBr pellet technique. The reactions were monitored by
thin-layer chromatography (TLC) using silica gel GF254 (EMD
Millipore, Billerica, MA). The melting points were determined on an
XT-4A melting point apparatus and are uncorrected. High-resolution
mass spectra time-of-flight (HRMS-TOF) were performed on an AutoSpec
Premier P776 mass spectrometer (Waters Corp., Milford,. MA). X-ray
diffraction analysis was performed using an Apex Duo diffractometer
(Bruker AXS GmbH., Karlsruhe, Germany). All chemicals and solvents
were used as received without further purification unless otherwise
stated. Column chromatography was performed on silica gel (200–300
mesh).
The materials were purchased from Adamas-β Ltd.
(Shanghai China). Compounds
to the literature.17 (link) Compounds