Synthesis and characterization of novel compounds

All compounds were fully characterized
by spectroscopic data. The NMR spectra were recorded on a Bruker DRX500
or DRX600. Chemical shifts (δ) are expressed in parts per million, J values are given in hertz, and deuterated dimethyl sulfoxide
(DMSO)-d₆ or CDCl₃ was used
as a solvent. IR spectra were recorded on an FTIR Thermo Nicolet Avatar
360 using a KBr pellet. The reactions were monitored by thin-layer
chromatography (TLC) using silica gel GF₂₅₄. The melting
points were determined on an XT-4A melting point apparatus and were
uncorrected. HRMS were performed on an Agilent LC/MSD TOF instrument.
X-ray diffraction was carried out by APEX DUO.
All chemicals
and solvents were used as received without further purification unless
otherwise stated. All chemicals were purchased from Adamas-β.
Column chromatography was performed on silica gel (Qingdao, 200–300
mesh). Compounds 1 were prepared according to the literature.^{50 (link),51 (link)}