Lcms it tof system

All chemicals purchased from commercial suppliers were used without further purification. Melting points (M.p.) were detected on an Electrothermal IA9200 melting point device (Staffordshire, UK) and are uncorrected. IR spectra were recorded on an IRPrestige-21 Fourier Transform IR spectrophotometer (Shimadzu, Tokyo, Japan). NMR (¹H and ¹³C) analyses were performed on an NMR spectrometer (Bruker, Billerica, MA, USA). HRMS spectra were recorded on a LCMS-IT-TOF system (Shimadzu, Kyoto, Japan). Thin-Layer Chromatography (TLC) was applied to monitor the progress of each chemical reaction and check the purity of each derivative.

Whole chemicals employed in the synthetic procedure were purchased from Sigma-Aldrich Chemicals (Sigma-Aldrich Corp., St. Louis, MO, USA) or Merck Chemicals (Merck KGaA, Darmstadt, Germany). Melting points of the obtained compounds were determined by MP90 digital melting point apparatus (Mettler Toledo, OH, USA) and were uncorrected. The IR spectra were obtained on a Shimadzu, IR Prestige-21 (Shimadzu, Tokyo, Japan). ¹H NMR, HSQC, HMBC, COSY and ¹³C NMR spectra of the synthesised compounds were registered by a Bruker 300 MHz and 75 MHz digital FT-NMR spectrometer (Bruker Bioscience, Billerica, MA, USA) in DMSO-d₆, respectively. Splitting patterns were designated as follows: s: singlet; d: doublet; t: triplet; m: multiplet in the NMR spectra. Coupling constants (J) were reported as Hertz. M + 1 peaks were determined by Shimadzu LC/MS ITTOF system (Shimadzu, Tokyo, Japan). All reactions were monitored by thin-layer chromatography (TLC) using Silica Gel 60 F254 TLC plates (Merck KGaA, Darmstadt, Germany).

5-Phenyl-1,3,4-oxadiazole-2-thiol (98%) was purchased from Alfa Aesar (Karlsruhe, Germany), whereas other reagents were purchased from other commercial suppliers. Melting points (M.p.) were determined on an Electrothermal 9100 melting point apparatus (Weiss-Gallenkamp, Loughborough, UK) and are uncorrected. IR spectra were recorded on an IRPrestige-21 Fourier Transform Infrared spectrophotometer (Shimadzu, Tokyo, Japan). ¹H-NMR and ¹³C-NMR spectra were recorded on a Varian Mercury-400 FT-NMR spectrometer (Agilent, Palo Alto, CA, USA). Mass spectra were recorded on a Shimadzu LCMS-IT-TOF system (Shimadzu, Kyoto, Japan). Thin Layer Chromatography (TLC) was performed on TLC Silica gel 60 F254 aluminium sheets (Merck, Darmstadt, Germany) to check the purity of the compounds.