Esi q tof premier xe spectrometer

Column chromatography was performed on silica gel 60 with 0.1% of CA (230–400 mesh ASTM, Merck) using a solvent mixture of CHCl₃/CH₃OH/H₂O (65 : 25 : 4, v/v/v). Analytical TLC was performed on Merck Kieselgel 60 F₂₅₄ plates (0.2 mm silica gel with a fluorescent indicator UV254) with mixtures of CHCl₃/CH₃OH/H₂O (65 : 25 : 4, v/v/v) as the developing system. Products were detected by spraying the plates with a solution of 10 g of Ce(SO₄)₂ and 20 g of phosphoromolibdenic acid in 1 L of 10% H₂SO₄ followed by heating or 0.05% primuline solution acetone/H₂O (8 : 2, v/v) followed by UV (365 nm) visualization. All the NMR spectra were recorded using a Bruker Avance II 600 MHz spectrometer (Brüker, Billerica, MA, USA). High-resolution mass spectra (HRMS) were obtained using an electron spray ionization (ESI) technique on a Waters ESI-Q-TOF Premier XE spectrometer.

TLC analyses used to monitor the progress of reactions were performed on 0.2 mm silica gel 60 F254 plates (Merck KGaA, Darmstadt, Germany) with a mixture of hexane and ethyl acetate or chloroform, methanol, and acetic acid in various ratios. Primuline spray (0.05% in acetone:water, 80:20, v/v) was used as a visualization reagent. Visualization was determined using UV light (λ = 254 and 365 nm). Compounds were also detected by spraying the plates with an H₂SO₄/CH₃OH mixture (1:1, v/v), followed by heating to 120–200 °C. Products were purified using chromatography on silica gel columns (Puriflash silica HP 50 μm, Interchim, Montluçon, France). NMR spectra (¹H, ¹³C, DEPT-135, COSY, HMQC, HMBC) were recorded on a Jeol 400 MHz Year Hold Magnet spectrometer (Jeol Ltd., Tokyo, Japan). Chemical shifts were referenced to the residual solvent signal (CDCl₃, 99.8 atom % D, δH = 7.26, δC = 77.00). ATR-IR spectra were collected using a Nicolet iS10 spectrometer (Thermo Fisher Scientific, Waltham, MA USA). Spectra were obtained from 4000 cm⁻¹ to 520 cm⁻¹ at 32 scans, with a spectral resolution of 4 cm⁻¹ and a blank window for background. HRMS spectra were recorded using the ESI technique on an ESI-Q-TOF Premier XE spectrometer (Waters Corp., Milford, MA, USA). Melting points (m.p., uncorrected) were determined on a Boetius apparatus (Nagema, Dresden, Germany).