Model dsc 60

Commercial reagents were obtained from Sigma–Aldrich (St. Louis, MI, USA). Melting points were determined by differential scanning calorimetry with a Shimadzu calorimeter (Model DSC-60). Fourier-transformed infrared (FTIR) spectra were obtained with ThermoScientific spectrometer (Model Nicolet iS10). ¹H- and ¹³C-NMR spectra were obtained with VARIAN 400-MR and 500-MR spectrometers. High-performance liquid chromatography with detection by photodiode arrays (HPLC-PDA) was performed with Shimadzu LC20AD apparatus using a Kromasil 100-5C18 column (4.6 mm × 250 mm) and SPD-M20A detector (Diode Variety). Ultraviolet-visible measurements were performed in a Femto scanning spectrophotometer (Model 800XI). High-resolution mass spectrometry (Orbitrap-HRMS) analysis was performed using a QExactive Hybrid Quadrupole Orbitrap Mass Spectrometer (Thermo Fisher Scientific, Waltham, MA, USA) with electrospray ionization (ESI) using solutions of the compounds (1 µg/mL) prepared in a 7:3 ratio of water:methanol fortified with 0.1% formic acid and 5 mM ammonium formate.