Agilent 500 mhz nmr

Melting points were recorded on a Thermocouple digital melting point apparatus and are uncorrected. IR spectra were recorded as powders using a Bruker VERTEX 70 FT-IR Spectrometer (Bruker Optics, Billerica, MA, USA) with a diamond attenuated total reflectance (ATR) accessory by using the thin-film method. For column chromatography, Kieselgel 60 (0.063–0.200 mm) (Merck KGaA, Frankfurt, Germany) was used as stationary phase. NMR spectra were obtained as CDCl₃ or DMSO-d₆ solutions using Mercury 300 MHz (Varian Inc., Palo Alto, CA, USA) or Agilent 500 MHz NMR (Agilent Technologies, Yarnton, UK) spectrometers and the chemical shifts are quoted relative to the TMS peak. Low- and high-resolution mass spectra were recorded at an ionization potential of 70 eV using Synapt G2 Quadrupole 6 Time-of-flight mass spectrometer (Waters Corp., Milford, MA, USA) at the University of Stellenbosch Mass Spectrometry Unit. The synthesis and analytical data of compound 3 has been described before [30 (link)]. The ¹H- and ¹³C-NMR spectra of compounds 4–6 are listed in the Supplementary Materials.

The melting point values for the prepared compounds were recorded on a Thermocouple digital melting point apparatus. Their IR spectra were recorded as powders by using the thin-film method using a Bruker VERTEX 70 FT-IR Spectrometer (Bruker Optics, Billerica, MA, USA) with a diamond ATR (attenuated total reflectance) accessory. For purification by column chromatography, we employed Merck kieselgel 60 (0.063–0.200 mm) (Merck KGaA, Frankfurt, Germany) as the stationary phase. The proton and carbon-13 NMR spectra were obtained as CDCl₃ solutions using Varian Mercury 300 MHz NMR spectrometer (Varian Inc., Palo Alto, CA, USA) or Agilent 500 MHz NMR (Agilent Technologies, Oxford, UK) spectrometer and the chemical shifts are quoted relative to the residual proton in the solvent 7.25 ppm and 77.0 ppm for ¹H and ¹³C NMR spectra, respectively. Low and high-resolution mass spectra were recorded at the University of Stellenbosch Central Analytical Facility and the ionization potential of 70 eV by using Waters Synapt G2 Quadrupole time-of-flight mass spectrometer (Waters Corp., Milford, MA, USA).