Merck silica gel 60f 254 glass plates

Staralogs (Figure 1B) were synthesized according to precedent (Lopez et al., 2013 (link)). This protocol was adapted for synthesis of Star 27. Materials obtained commercially were reagent grade and were used without further purification. 1H NMR and 13C NMR spectra were recorded on Varian 400 (Palo Alto, CA) or Brucker 500 (Billerica, MA) spectrometers at 400 and 125 MHz, respectively. Low resolution mass spectra (LC/ESI-MS) were recorded on a Waters Micromass ZQ equipped with a Waters 2695 Separations Module and a XTerra MS C18 3.5 mm column (Waters). Reactions were monitored by thin layer chromatography (TLC), using Merck silica gel 60 F254 glass plates (0.25 mm thick). Flash chromatography was conducted with Merck silica gel 60 (230–400 mesh).

Melting points (m.p.) were determined using a SRS Opti Mel automated melting point instrument without correction. ¹H and 13C NMR spectra were recorded using TMS as the internal standard in DMSO-d₆ with a Bruker BioSpin GmbH spectrometer at 400 and 100 MHz, respectively. Mass spectra (MS) were recorded on Bruker amaZon SL mass spectrometer with an ESI or ACPI mass selective detector. Reactions progress and compounds were checked by TLC with Merck silica gel 60F-254 glass plates. All chemicals were purchased from commercial sources unless otherwise specified, and all the solvents were analytical grade. The purities of synthesized compounds were confirmed by HPLC with a dual pump Shimadzu LC-20A system equipped with a photo-diode array detector and a C18 column (250 × 4.6 mm, 5 μM YMC) and eluted with acetonitrile/water (47:53) containing 0.5% acetic acid at flow rate of 1.0 ml/min.

Melting points were measured on a Stuart Melting Point (SMP3) apparatus (Barloworld Scientific, UK) in open capillaries with uncorrected values. IR spectra were recorded on FTIR Spectrum One spectrophotometer (Perkin-Elmer, UK). NMR (¹H and ¹³C) were recorded at 25 °C on NMR Avance 600 spectrometer (Bruker, Germany) at 300 and 150 MHz for ¹H and ¹³C nuclei, respectively. All compounds were routinely checked by TLC with Merck silica gel 60 F-254 glass plates using the following solvent systems: petrolether/ethyl acetate/methanol 30:10:5, cyclohexane/ethyl acetate 1:1, cyclohexane/dichloromethane/methanol 10:18:2, dichloromethane/methanol 97:3 and 95:5. Spots were visualised by short-wave UV light and iodine vapour. Column chromatography was performed on silica gel 0.063–0.200 mm (Kemika, Croatia) and 0.040–0.063 mm (Merck, Germany), with the same eluents used in TLC. 1H-benzo[d][1,2,3]triazole (BtH), triphosgene, triethylamine (TEA), hydrazine hydrate, L-leucine, D-phenylglycine, DL-p-chlorophenylglycine and N-methyl-1,1-diphenylmethanamine were purchased from Sigma-Aldrich, USA. Primaquine, diphenylmethanamine and (4-chlorophenyl)(phenyl)methanamine were prepared from commercially available salts (Sigma-Aldrich) prior the use. All reactions with Primaquine were run light protected.