Thermo nicolet ft ir nexus spectrophotometer

Proton (¹H) and carbon (¹³C) NMR spectra were recorded on a Brüker 400 Ultra-shield™ spectrometer (Brüker, Rheinstetten, Germany) using DMSO-d₆ or CDCl₃ as solvent. IR spectra were recorded on a Thermo Nicolet FT-IR Nexus spectrophotometer (Thermo Nicolet, Madison, WI, USA) using KBr pellets for solid samples or NaCl plates for oil compounds. Elemental analysis was performed on a LECO CHN-900 Elemental Analyzer (LECO, Saint Joseph, MI, USA). The purity of all final compounds was 99% or higher. Chemicals were purchased from E. Merck (Darmstadt, Germany), Panreac Química S.A. (Barcelona, Spain), Sigma-Aldrich Quimica, S.A. (Madrid, Spain) and Acros Organics (Janssen Pharmaceuticalaan, Geel, Belgium). The synthesis of 34 out of the 40 compounds analysed in this work has been previously described [28 (link),29 (link)].

The NMR spectra (¹H and ¹³C) were recorded on a Bruker 400 Ultrashield^TM spectrometer (Rheinstetten, Germany) and are provided in the supplementary material. The samples were solved in CDCl₃ and TMS was used as an internal standard. IR spectra were obtained on a Thermo Nicolet FT-IR Nexus spectrophotometer (Thermo Nicolet, Madison, WI, USA) using KBr pellets for solids or NaCl plates for oil compounds. The HRMS spectra were recorded on a Thermo Scientific Q Exactive Focus mass spectrometer (Thermo Scientific™, Waltham, MA, USA) by direct infusion. For TLC assays, Alugram SIL G7UV254 sheets (Macherey-Nagel; Düren, Germany) were used. Column chromatography was performed with silica gel 60 (E. Merck KGaA, Darmstadt, Germany). Chemicals were purchased from E. Merck KGaA (Darmstadt, Germany), Panreac Química S.A. (Montcada i Reixac, Barcelona, Spain), Sigma-Aldrich Quimica, S.A. (Alcobendas, Madrid, Spain), and Acros Organics (Janssen Pharmaceuticalaan, Geel, Belgium).