Silica gel 60 m

Commercially available chemicals were of reagent grade and used as received. The reaction progress was monitored using LR-ESI-MS spectra and thin layer chromatography (TLC) using silica gel plates (Kieselgel 60F₂₅₄, E. Merck, Darmstadt, Germany). Column chromatography used for purification and isolation of compounds was performed on silica gel 60 M (0.040–0.063 mm, E. Merck, Darmstadt, Germany). Melting points were measured using Büchi (New Castle, DE, USA) Melting Point B-540 apparatus. All ¹H and ¹³C NMR spectra were recorded on a Bruker Avance III spectrometer operating at 500.13 (¹H) and 125.77 (¹³C) MHz and equipped with a 5 mm probe head with Z-gradient coils. The experiments were performed using pulse programs from standard Bruker library for samples dissolved in CDCl₃, DMSO-d₆, or MeOH-d₄. In each case, spectra were calibrated at residual solvent resonances. High resolution mass spectra were performed by the Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics PAS, on a LTQ Orbitrap Velos instrument, Thermo Scientific (Waltham, MA, USA). Synthetic procedures, physicochemical properties, and spectra related to synthesized compounds are included in the supplementary file.

Commercially available chemicals were of reagent grade and used as received. Purification of the compounds was performed by column chromatography on silica gel 60 M (0.040–0.063 mm, E. Merck, Darmstadt, Germany). Thin layer chromatography (TLC), using silica gel plates (Kieselgel 60F₂₅₄, E. Merck), was used to monitor reaction progress. A B-540 Melting Point apparatus (Büchi, New Castle, DE, USA) was used to measure melting points. The ¹H-NMR and ¹³C-NMR spectra, in DMSO-d₆ and CDCl₃, were recorded at the Department of Chemistry, University of Warsaw, using an AVANCE III HD 300 MHz spectrometer (Bruker, Billerica, MA, USA); shift values in parts per million are relative to the SiMe₄ internal reference. The resonance assignments were based on peak multiplicity and peak integration of recorded spectra, Multiplets were assigned as bs (broad singlet), s (singlet), d (doublet), t (triplet) dd (doublet of doublet), ddd (doublet of doublet of doublet) and m (multiplet). An LTQ Orbitrap Velos instrument (Thermo Scientific, Waltham, MA, USA) located at the Mass Spectrometry Laboratory of the Institute of Biochemistry and Biophysics PAS (Warsaw, Poland) was used to record high resolution mass spectra. A 6200 FT/IR spectrometer (Jasco, Easton, MD, USA) at the Laboratory of Optical Spectroscopy (Institute of Organic Chemistry PAS, Warsaw, Poland) was used to record IR spectra.