Qp5050a gas chromatograph mass spectrometer

The progress of the reactions was monitored by visualizing the thin layer chromatography (TLC) plates in an ultraviolet (UV) chamber, with a lamp irradiating at 254 nm. 18 The melting points were determined on an electrothermal digital apparatus and were not corrected. Infrared spectra were performed on a Fourier transform infrared (FT-IR) Varian 660 equipped with GladiATR (Varian, Palo Alto, CA, USA). Nuclear magnetic resonance (NMR) spectra were recorded on a Varian Mercury 300 MHz spectrometer. Deuterated chloroform was used as solvent and the residual hydrogen of chloroform (𝛿 = 7.22 ppm) was used as reference in the 1 H NMR. The signal of the carbon of CDCl 3 at 𝛿 = 77 ppm was used as reference in the 13 C NMR. Gas chromatography-mass spectrometry (GC-MS) was conducted with a Shimadzu QP5050A gas chromatograph-mass spectrometer (Shimadzu, Japan) using a glass capillary column (25 m × 0.25 mm) DB-1. Electron impact (70 eV) was employed to ionize the molecules before fragmentation in the mass spectrometer chamber. The quality (purity) of the compounds was assessed by the 1 H and 13 C NMR spectroscopy and their identity confirmed by the combined interpretation of NMR, IR, and MS.

Reagents and solvents were purified according to the usual procedures described in the literature. 14 The melting points were determined on an electrothermal digital apparatus and were uncorrected. IR spectra were recorded on a PerkinElmer Spectrum 1000 grating spectrometer (PerkinElmer, Waltham, MA) using sodium chloride liquid film and scanning from 500 to 4000 cm -1 . NMR spectra were recorded on a Varian Mercury 300 MHz spectrometer (Varian, Palo Alto, CA). The solvent employed was deuterated chloroform, and the signal of the hydrogen of CHCl 3 was used as the reference (𝛿 = 7.22) in the 1 H NMR. The signal of the carbon of CDCl 3 was used as the reference (𝛿 = 77) in the 13 C NMR. GC-MS was conducted with a Shimadzu QP5050A gas chromatograph-mass spectrometer (Shimadzu, Kyoto, Japan) using a glass capillary column (25 m × 0.25 mm) DB-1.