Gf 254 type 60 silica gel

Melting points were determined using a Kofler Thermogerate apparatus (Reichert, Wien, Austria) and are uncorrected. Specific rotations were recorded on a DIP-370 optical polarimeter (JASCO, Tokio, Japan). Infrared spectra were recorded on a UATR Spectrum two (Perkin Elmer, Waltham, MA, USA, films on NaCl). Nuclear magnetic resonance spectra were recorded on a Mercury 300 apparatus (Varian, Palo Alto, CA, USA). Mass spectra were obtained on a MS 50 TC mass spectrometer (Kratos, Manchester, UK). Thin layer chromatography (tlc) was performed using GF-254 type 60 silica gel (Merck, Kenilworth, NJ, USA) and EtOAc/hexane mixtures as eluents; the tlc spots were visualized with a Hanessian stain (dipping into a solution of 12.5 g of (NH₄)₄Mo₇O₂₄·4H₂O, 5 g of Ce(SO₄)₂·4H₂O and 50 mL of H₂SO₄ in 450 mL of H₂O, and warming). Column chromatography was carried out using Merck type 9385 silica gel.

Melting points were determined on a Kofler Thermogerate apparatus and were uncorrected. Infrared spectra were recorded on a JASCO FT/IR-400 spectrophotometer. Nuclear magnetic resonance spectra were recorded, unless otherwise specified, on a Bruker AM-400 instrument using deuterated chloroform or dimethylsulfoxide solutions containing tetramethylsilane as an internal standard. ESI/MS experiment was carried out on an UHPLC Eksigent1 coupled with MS detector ABSciex1, Triple Quad 4500 model equipment. HRMS-ESI-MS experiments were performed using a Thermo Scientific Exactive Plus Orbitrap spectrometer with a constant nebuliser temperature of 250 °C. The experiments were carried out in positive or negative ion mode, with a scan range of m/z 300.00–1510.40 and a resolution of 140,000. The samples were infused directly into the ESI source via a syringe pump at flow rates of 5 µL·min⁻¹ through the instrument’s injection valve. Thin layer chromatography (TLC) was performed using Merck GF-254 type 60 silica gel. Column chromatography was carried out using Merck type 9385 silica gel. The purity of the compounds was determined by TLC and high-resolution mass spectrometry (HRMS) and for 4s by HLPC (Figure S8).