Precoated silica gel 60 f254

The melting points (in °C) were measured with a Stuart melting point apparatus and are uncorrected. Thermo Fisher SCIENTIFIC Nicolet IS10 Spectrometer (v in cm⁻¹) was used to record IR spectra (KBr) at Mansoura University's Faculty of Pharmacy. At the NMR facility, Faculty of Pharmacy, Mansoura University, Egypt, ¹H-NMR and ¹³C-NMR spectra were acquired in a BRUKER 400 MHz using TMS as an internal standard (chemical shifts in ppm, units). Thin layer chromatography (TLC) plates with Silica gel 60 F254 precoated (E. Merck) were used to monitor reaction completion, and the spots were seen using UV light (366 nm). Sigma-Aldrich provided all of the compounds, which were utilized without additional purification. Compounds 2^{27 (link)}, 4^{32 (link)} and 6³⁹ were synthesized according to the previously reported procedures.

All the solvents and regents were purchased from Sigma Aldrich (Gillingham, UK) and they were used in the reactions without purification. The progress of each reaction was monitored by ascending thin layer chromatography (TLC) using TLC aluminum sheets, silica gel 60F₂₅₄ precoated (Merck, Darmstadt, Germany), and locating the spots using UV light as the visualizing agent or iodine vapor. The melting points for the 4-thiazolidinone conjugates were carried out using an open capillary method and they are uncorrected. ¹H NMR spectra were obtained on a Bruker DRX-400 MHz NMR spectrometer in DMSO-d₆ (δ in ppm relative to tetramethylsilane (TMS) as an internal standard) and ¹³C NMR spectra were recorded (DMSO-d₆) on a Bruker DRX-100 MHz spectrometer (Bruker BioSpin MRI GmbH, Ettlingen, Germany). High-resolution mass spectra (HRMS) were obtained using an Agilent 6520 (QTOF) ESI-HRMS model (Thermo Fisher Scientific, Waltham, MA, USA).

All the chemicals were purchased from Sigma-Aldrich, and all the solvents for the use were of laboratory grade. The materials for in vitro evaluation were obtained from Sigma-Aldrich Ltd. The reactions were monitored by thin layer chromatography (TLC) on precoated silica gel 60 F254 (Merck, Darmstadt, Germany), and spots were visualized with UV light. Merck silica gel (80–120 mesh; Merck, Darmstadt, Germany) was used for column chromatography. All the synthesized compounds were purified by recrystallization and column chromatography. Melting points were determined via an open capillary method and were uncorrected. IR spectra were recorded on a Perkin-Elmer FT-IR 240-C Spectrophotometer using KBr optics (Perkin-Elmer, Waltham, MA, USA). Next, 1H-NMR spectra were recorded on Gemini Varian (Varian, Palo Alto, CA, USA) 200 MHz, Bruker (Bruker Bioscience, Billerica, MA, USA) AV 300 MHz, and Unity (Varian) 400 MHz spectrometer in DMSO-d6 or CDCl3 using TMS as an internal standard. Electron impact (EI) and chemical ionization mass spectra were recorded on a VG 7070 H instrument (Micromass, St Leonards-0n Sea, UK) at 70 eV.