Analytical Characterization of Organic Compounds

Reagents and solvents were purchased from Fischer Scientific, Sigma Aldrich™, Fluorochem™, or Alfa Aesar™, were of analytical reagent grade and were used as received. ¹H and ¹³C-NMR spectra were recorded, in specified deuterated solvents, (purchased from Apollo Scientific™), at room temperature on Bruker™ Avance-400 (¹H, ¹³C) (operating at 400.13 MHz) spectrometers and are reported as follows: chemical shift δ (ppm) (number of protons, multiplicity, coupling constant J (Hz) (if applicable), assignment). Multiplicities are reported using the following abbreviations: s (singlet), d (doublet), t (triplet), q (quartet) and m (unresolved multiplet). All ¹³C-NMR spectra were proton-decoupled and carbons are numbered according to the IUPAC systematic name. The ¹H and ¹³C chemical shifts are reported using the residual signal of deuterated solvent as the internal reference (for CDCl₃: δ_H = 7.26 ppm; δ_C = 77.16 ppm and for deuterated d⁶-DMSO: δ_H = 2.50 ppm; δ_C = 39.51 ppm). All chemical shifts are quoted in parts per million, relative to tetramethylsilane (δ_H, δ_C = 0.00 ppm). All coupling constants are ³J_HH unless otherwise stated. Electrospray Ionisation (ESI) mass spectra, for LC-MS results were obtained using a TQD mass spectrometer (Waters UK Ltd., Manchester, UK). High-resolution mass spectra were obtained with an LCT Premier XE mass spectrometer (Waters UK Ltd., Manchester, UK); all were obtained by the Durham University Mass Spectrometry service. ASAP mass spectra were obtained using a Waters™ Synapt G2s apparatus. Thin-Layer Chromatography was performed using Merck TLC Aluminium oxide 60 F254 with glass backing. Plates were stained with potassium permanganate solution, where required and visualised using UV light. Column chromatography refers to purification by applying the mixture, dissolved in a minimum amount of dichloromethane, onto silica gel (40–63 µm mesh size) with the stated solvent system.