Agilent 500 mhz nmr spectrometer

The melting point (mp.) values of the prepared compounds were recorded on a Thermocouple digital melting point apparatus (Mettler Toledo LLC, Columbus, OH, USA) and are uncorrected. Their infrared (IR) spectra were recorded using the thin-film method on a Bruker VERTEX 70 FT-IR Spectrometer (Bruker Optics, Billerica, MA, USA) equipped with a diamond attenuated total reflectance (ATR) accessory. The Merck kieselgel 60 (0.063–0.200 mm) (Merck KGaA, Frankfurt, Germany) was used as a stationary phase for column chromatography. The proton (¹H-) and carbon-13 (¹³C-) nuclear magnetic resonance (NMR) spectra of the prepared compounds were obtained as CDCl₃ or dimethyl sulfoxide-d₆ (DMSO-d₆) solutions using Agilent 500 MHz NMR spectrometer (Agilent Technologies, Oxford, UK). The chemical shifts are quoted relative to the tetramethylsilane (TMS) peak as an internal reference standard. The high-resolution mass spectra were recorded at the University of Stellenbosch using a Waters Synapt G2 Quadrupole Time-of-flight mass spectrometer (Waters Corp., Milford, MA, USA) at an ionization potential of 70 eV. The synthesis and analytical data for 2,4-dihydroxy-5-iodoacetophenone, were reported in our previous investigation [23 (link)].

High-performance liquid chromatography (HPLC) analysis was conducted on the Agilent 1200 HPLC system (Agilent Technologies Inc., USA) or Thermo Scientific Dionex Ultimate 3000 (Thermo Fisher Scientific Inc., USA) with a reverse-phase Spursil C18 column (5 μ, 4.8 × 250 mm). Semi-preparative HPLC was performed on a Shimadzu LC-20-AT system. HPLC electrospray ionization MS (HPLC-ESI-MS) was performed on the Thermo Fisher LTQ Fleet ESI-MS spectrometer (Thermo Fisher Scientific Inc., USA). High-resolution ESI-MS analysis was conducted on the 6230B Accurate Mass TOF LC/MS System (Agilent Technologies Inc., USA). NMR data were collected on the Agilent 500 MHz NMR spectrometer (Agilent Technologies Inc., USA) and Bruker AVANCE III HD 600 spectrometers (Bruker Daltonics Inc., USA).

The melting point values of the test compounds were recorded on a Thermocouple digital melting point apparatus (Mettler Toledo LLC, Columbus, OH, USA). The infrared (IR) spectra were recorded using the thin-film method on a Bruker VERTEX 70 FT-IR Spectrometer (Bruker Optics, Billerica, MA, USA) equipped with an ATR (diamond attenuated total reflectance) accessory. Merck kieselgel 60 (0.063–0.200 mm) (Merck KGaA, Frankfurt, Germany) was used as a stationary phase for column chromatography. The ¹H-NMR and ¹³C-NMR spectra of the prepared compounds were obtained as deuterated dimethyl sulfoxide ((CD₃)₂SO) solutions using Agilent 500 MHz NMR spectrometer (Agilent Technologies, Oxford, UK) operating at 500 MHz and 125 MHz for ¹H and ¹³C, respectively. The chemical shifts are quoted relative to tetramethylsilane (TMS) used as an internal reference standard (δ = 0.00 ppm) or a residual protonated solvent. The high-resolution mass spectra were recorded at an ionization potential of 70 eV using Micromass Autospec-TOF (double focusing high resolution) instrument (Waters Corp., Milford, MA, USA). The synthesis and analytical data for 2-amino-5-iodobenzamide (1) have been reported in our previous study [25 (link)]. Recombinant human AChE (BioLegend) and BChE (Cloud-Clone Corp.) were purchased via Biocom Africa (Pty) Ltd. (Centurion, Pretoria, South Africa).

The melting points of the prepared compounds were recorded on a Thermocouple digital melting point apparatus and are uncorrected. Their IR spectra were recorded as powders by using the thin-film method on a Bruker VERTEX 70 FT-IR Spectrometer (Bruker Optics, Billerica, MA, USA) equipped with a diamond ATR (attenuated total reflectance) accessory. The Merck kieselgel 60 (0.063–0.200 mm) (Merck KGaA, Frankfurt, Germany) was used as stationary phase for column chromatography. The ¹H- and ¹³C-NMR spectra of the prepared compounds were obtained as CDCl₃ or DMSO-d₆ solutions using the Agilent 500 MHz NMR spectrometer (Agilent Technologies, Oxford, UK) and the chemical shifts are quoted relative to the TMS peak. The low- and high-resolution mass spectra were recorded at the University of Stellenbosch using a Waters Synapt G2 Quadrupole Time-of-flight mass spectrometer (Waters Corp., Milford, MA, USA) at an ionization potential of 70 eV. The synthesis and analytical data of the 2–(4-halogenophenyl)-4-chloroquinazolines 9a and 9 b have been described before¹⁸ (link). Copies of ¹H- and ¹³C-NMR spectra of compounds 6a–e, 7a–e, 8a–e, 10a–j are included as Supplementary Material.

The melting point values of the test compounds were recorded on a Thermocouple digital melting point apparatus (Mettler Toledo LLC, Columbus, OH, USA). The infrared (IR) spectra were recorded using the thin-film method on a Bruker VERTEX 70 FT-IR Spectrometer (Bruker Optics, Billerica, MA, USA) equipped with an ATR (diamond attenuated total reflectance) accessory. Merck kieselgel 60 (0.063–0.200 mm) (Merck KGaA, Frankfurt, Germany) was used as a stationary phase for column chromatography. The ¹H NMR and ¹³C NMR spectra were recorded as deuterated chloroform (CDCl₃) or dimethyl sulfoxide ((CD₃)₂SO) solutions using Agilent 500 MHz NMR spectrometer (Agilent Technologies, Oxford, UK) operating at 500 MHz and 125 MHz for ¹H and ¹³C, respectively. The chemical shifts are quoted relative to tetramethylsilane (TMS) used as an internal reference standard (δ = 0.00 ppm) or to residual protonated solvent. Data are presented as follows: chemical shift (ppm), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, sept = septet, m = multiplet, br = broad), coupling constant J (Hz), and integration. The high-resolution mass spectra were recorded at an ionization potential of 70 eV using Micromass Autospec-TOF (double focusing high resolution) instrument (Waters Corp., Milford, MA, USA).