Spectrospin ac 300 spectrometer

NMR spectra were recorded with a Bruker-Spectrospin AC 300 spectrometer operating at 300 MHz for ¹H and 75 MHz for ¹³C using tetramethylsilane as the internal standard (0.00 ppm) in CDCl₃ as solvent. The following abbreviations were used to explain the multiplicities: bs = broad singlet, s = singlet, d = doublet, m = multiplet.
Elemental analyses were performed on a Perkin Elmer 2400 Series II Elemental CHNS analyzer. Materials: thin-layer chromatography (TLC): TLC plates (Merck, silica gel 60 F₂₅₄ 0.2 mm 200 × 200 nm); substances were detected using UV light at 254 nm.

NMR spectra were recorded with a Bruker-Spectrospin AC 300 spectrometer (Rheinstetten, Germany) operating at 300 MHz for ¹H and 75 MHz for ¹³C. The following abbreviations were used to explain the multiplicities: bs = broad singlet, s = singlet, dd = doublet of doublet, d = doublet, t = triplet, m = multiplet. Elemental analyses were performed on a Perkin Elmer 2400 Series II Elemental CHNS analyzer (Waltham, MA, USA). Electrospray ionization (ESI) mass spectra were collected using a Q-TOF instrument supplied by WATERS (Agilent, Palo Alto, CA, USA). Materials: thin-layer chromatography (TLC): TLC plates (Merck, silica gel 60 F₂₅₄ 0.2 mm 200 × 200 nm) (Darmstadt, Germany); substances were detected using UV light at 254 nm.