Kbr disk

Carbon-13 nuclear magnetic resonance (¹³C NMR) and proton (¹H) NMR spectra were detected with a Brucker 300 spectrometer. Infrared (IR) spectra were acquired on a Perkin- Elmer spectrometer (KBr disk) (Perkin-Elmer, Waltham, MA). Chemical shifts were reported as ppm and tetramethylsilane was used as an internal standard. Mass spectra (MS) were recorded with an Agilent spectrometer (Agilent technologies 9575c inert MSD, USA). A Costech elemental analysis instrument (Costech ESC 4010, Italy) was achieved as the elemental assessment and was within 0.4 % of the calculated value. A hot stage apparatus (Electrothermal, Essex, UK) was used to attain melting points.

All melting points were taken on a hot stage apparatus (Electrothermal, Essex, UK) and were reported uncorrected. IR spectra were recorded with a Perkin-Elmer spectrometer (KBr disk) (PerkinElmer, Waltham, MA, USA). NMR spectra were recorded on a Bruker Avance 300 spectrometer (300 MHz for ¹H NMR, 75 MHz for ¹³C NMR). Mass spectra were obtained with an Agilent spectrometer (9575c inert MSD; Agilent Technologies, Santa Clara, CA, USA). Chromatographic separations were performed on a silica gel column by gravity chromatography (Kieselgel 40, 0.063–0.200 mm; Merck) or flash chromatography (Kieselgel 40, 0.040–0.063 mm; Merck). Yields are given after purification, unless otherwise stated. All compounds were named following IUPAC guidelines as defined by ChemBioDraw Ultra 12.0 software.