6320 ion trap mass spectrometer

NMR spectra were obtained at 300 or 500 (¹H) and 75 or 125 (¹³C) MHz using Bruker ARX300 or Bruker DX-2 500 [QNP probe or multinuclear broadband observe (BBO) probe, respectively] spectrometers. Column chromatography was performed with 230–400 mesh silica gel. The melting points were determined using capillary tubes with a Mel-Temp apparatus and are uncorrected. IR spectra were obtained using a PerkinElmer 1600 series FTIR spectrometer on salt plates or as KBr pellets. ESIMS analyses were recorded on a FinniganMAT LCQ Classic mass spectrometer. APCI–MS analyses were performed using an Agilent 6320 ion trap mass spectrometer. EI/CIMS analyses were obtained with a Hewlett-Packard Engine mass spectrometer. All mass spectral analyses were performed at the Campus-Wide Mass Spectrometry Center of Purdue University. HPLC analyses were carried out on a Waters 1525 binary HPLC pump/Waters 2487 dual λ absorbance detector system using a 5 μm C18 reverse phase column. All reported yields refer to pure isolated compounds. Chemicals and solvents were of reagent grade and used as obtained from commercial sources without further purification. The purities of all of the biologically tested compounds were ≥95% as estimated by HPLC or determined by elemental analysis. For HPLC, the peak area of the major product was ≥95% of the combined total peak areas when monitored by a UV detector at 254 nm.