Agilent 6120 single quadrupole liquid chromatography tandem mass spectrometer lc ms

All reactions were performed in glassware under a positive pressure of argon. Flash column chromatography was performed on a Teledyne ISCO CombiFlash Rf 200 system (Isco, Inc., Lincoln, NE, USA) using silica gel 60 (230–400 mesh). Thin layer chromatography (TLC) analyses were performed on EMD 250 μm Silica Gel 60 F254 plates (Merck KGaA, Darmstadt, Germany) and visualized by quenching of UV fluorescence (λ_max = 254 nm) or by staining with ceric ammonium molybdate. ¹H-NMR spectra were recorded on a Varian Inova-400 instrument (Varian, Inc., Palo Alto, CA, USA). Chemical shifts are reported in ppm (δ) relative to the residual solvent signals of the solvent (δ 7.26 for CHCl₃), coupling constants (J) are reported in Hz and the multiplicities are presented as follows: s = singlet, brs = broad singlet, d = doublet, t = triplet, q = quartet, and m = multiplet. Mass spectra were acquired on Agilent 6120 Single Quadrupole Liquid Chromatography tandem Mass Spectrometer (LC/MS) (Agilent Technologies, Santa Clara, CA, USA). High-resolution mass spectrum was acquired by the Mass Spectrometry Facility at the University of Austin.