Avance ultrashield spectrometer

General experimental procedures Reagents and solvents were purchased from Sigma Aldrich, Acros Organics, and Cayman Chemicals and used without further purification. Reaction’s progress was qualitatively analyzed by thin-layer chromatography performed on precoated silica gel plates (Merk, Kieselgel 60 F-254, 0.2 mm). Compound spots were visualized by UV light (254 nm). Compounds were characterized by ¹H-NMR and ¹³C-NMR using a 400 MHz Bruker Avance Ultrashield Spectrometer (Switzerland); the spectra were obtained in ppm using automatic calibration to the residual proton peak of the solvent, DMSO-d₆. The ¹H NMR data are presented as follows: chemical shift (δ ppm), multiplicity (s = singlet, d = doublet, dd = doublet of doublet, t = triplet, q = quartet, m = multiplet), coupling constants (Hz), and integration. The ¹³C NMR analyses were reported in terms of chemical shift. ¹H and ¹³C NMR spectra for all compounds are included in the Supplementary material. HRMS data were acquired using a Thermo QExactive Plus mass spectrometer equipped with an electrospray ionization source (Thermo Fisher Scientific).

Bulk solvents and chemicals were purchased through local vendors without any further purification or distillation. The progress of reactions was qualitatively analyzed by thin layer chromatography performed on Merck aluminum thin layer chromatography plates (DC Kieselgel 60 F254). An ultraviolet lamp was used to visualize the thin layer chromatography plate. New compounds were characterized by ¹H-NMR and ¹³C-NMR using a 400 mHz Avance Ultrashield spectrometer (Bruker, Ettlingen, Germany); the spectra were obtained in parts per million using automatic calibration to the residual proton peak of the solvent, ie, dimethylsulfoxide (DMSO)-d6. The infrared spectra of the synthesized compounds were recorded on a Thermo-Nicolet Avatar 360 FT-IR, (Thermo Fisher Scientific, Rockville, MD, USA). A liquid chromatography-tandem mass spectrometry system (API 3200, Applied Biosystems-MDS SCIEX, Foster City, CA, USA), employing positive mode, was used to characterize the compounds, with the electrospray ionization source operated at 5.0–5.5kV, the capillary heater at 350°C, and a sheath gas pressure of 45 psi. The enzyme activity plates were read using a universal microplate reader (ELx800, Bio-Tek Instruments Inc, Winooski, VT, USA).