Dalton microtof q 2 spectrometer

Chemical reagents and solvents were purchased from Leyan-Shanghai Haohong Scientific Co., Ltd., Shanghai, China. Reactions were monitored by TLC plates coated with 0.25 mm silica gel 60 F₂₅₄ and visualized by UV irradiation (254 nm). Flash column chromatography employed silica gel (particle size 32–63 μm, Qingdao Haiyang Chemicals, Qingdao, China). NMR spectra were acquired on an AV-400 instrument (Bruker BioSpin, Faellanden, Switzerland) with chemical shifts reported in ppm and referenced to CDCl₃. IR spectra were obtained with a Vertex-70 instrument (Bruker Optics, Billerica, MA, USA). High-resolution mass spectra were obtained with a Dalton micrOTOF-Q II spectrometer (Bruker Optics, Billerica, MA, USA) and reported as m/z. Melting points were determined with an X-4 digital melting point apparatus and uncorrected (Tech Instrument, Beijing, China). The characterization data of known compounds 1–9, 11, and 13–17 are in agreement with previous reports [17 (link),18 (link),20 (link),23 (link),32 (link),45 (link)] and listed in the Supplementary Materials. The characterization spectra of new compounds 10, 12, 18–20 are also provided in the Supplementary Materials.

General chemical reagents and solvents were obtained from commercial suppliers. All reactions were monitored by thin layer chromatography on plates coated with 0.25 mm silica gel 60 F254 (Qingdao Haiyang Chemicals, Qingdao, China). TLC plates were visualized by UV irradiation (254 nm, Shanghai Peiqing Sci & Tech, Shanghai, China). Flash column chromatography employed silica gel (particle size 32–63 μm, Qingdao Haiyang Chemicals, Qingdao, China). Melting points were determined with a Thomas-Hoover melting point apparatus (Thomas Scientific, Swedesboro, NJ, USA) and uncorrected. NMR spectra were obtained with a Bruker AV-400 instrument (Bruker BioSpin, Faellanden, Switzerland) with chemical shifts reported in parts per million (ppm, δ) and referenced to CDCl₃ or DMSO-d₆. The NMR spectra of compounds 11, 15, 16, 20–23, 25, and 27–29 were provided in Supplementary Materials (Figures S1–S22). IR spectra were recorded on a Bruker Vertex-70 spectrometer (Bruker Optics, Billerica, MA, USA). High-resolution mass spectra were reported as m/z and obtained with a Dalton micrOTOF-Q II spectrometer (Bruker Daltonics, Billerica, MA, USA).

All reagents were purchased from commercial sources and used without purification unless specified. Acetonitrile, pyridine and CH₂Cl₂ were refluxed with CaH₂ and distilled prior to use. THF was dried with LiAlH₄ and distilled prior to use. Thin-layer chromatography was performed using silica gel GF-254 plates (Qingdao Chemical Company, Qingdao) detected by UV (254 nm) or charting with 10% sulfuric acid in ethanol. Column chromatography was performed on silica gel (200–300 mesh, Qingdao Chemical Company, Qingdao). NMR spectra were recorded on a Bruker AV400 spectrometer. Chemical shifts (δ) are reported in ppm and coupling constants (J) are reported in Hz. Then, ¹H and ¹³C NMR spectra were calibrated with TMS as an internal standard. The specific rotation was measured on a Rudolph autopol IV polarimeter. ESI-MS was acquired with a Bruker Dalton microTOFQ II spectrometer.