0.25 mm silica gel plates

Unless noted otherwise, all starting materials and reagents were obtained commercially and were used without further purification. All solvents utilized for routine product isolation and chromatography were of reagent grade and glass-distilled, and reaction flasks were dried at 100°C before use. Flash column chromatography was performed using silica gel 60 (230–400 mesh, Merck, Kenilworth, NJ, USA) with the indicated solvents. Thin-layer chromatography (TLC) was performed using 0.25-mm silica gel plates (Merck, Kenilworth, NJ, USA). Mass spectra were obtained using an Agilent 6530 Q-TOF (Santa Clara, CA, USA) instrument. Infrared spectra were recorded on a JASCO FT-IR-4200 spectrometer (Tokyo, Japan). ¹H and ¹³C spectra were recorded on a Brucker Analytik ADVANCE digital 500 (500 MHz) (Billerica, MA, USA) and BRUKER AVANCE-800 (Billerica, MA, USA). Chemical shifts are expressed in parts per million (ppm, δ) downfield from tetramethylsilane and are referenced to the deuterated solvent. ¹HNMR data are reported in the order of chemical shift, multiplicity (s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; bs, broad singlet; and/or multiple resonances), number of protons, and coupling constant in hertz (Hz).

All the chemicals used were of analytical grade and obtained from Himedia and SD Fine Chemicals. The completion of the reaction, the purity of the compounds checked by TLC using E-Merck 0.25 mm silica gel plates, and visualization were accomplished with UV light. Melting points were determined on Bio Technics India melting point apparatus and were uncorrected. ¹H NMR spectra were recorded on an Avance-300 MHz in CDCl₃ solvent using TMS as an internal standard (chemical shifts in δ, ppm). The IR spectra were recorded on Rkin Elmer Spectrum BX-1 spectrometer by using KBr disc. The mass spectra were recorded on a LC-MSD-Trap-SL.

Unless noted otherwise, all starting materials and reagents were obtained from commercial suppliers and were used without further purification. Tetrahydrofuran was distilled from sodium benzophenone ketyl. Dichloromethane was freshly distilled from calcium hydride. All solvents used for routine isolation of products and chromatography were reagent grade. Air- and moisture-sensitive reactions were performed under argon atmosphere. Flash column chromatography was performed using silica gel 60 (230–400 mesh, Merck, Darmstadt, Germany) with the indicated solvents. Thin-layer chromatography was performed using 0.25 mm silica gel plates (Merck). ¹H-NMR data were reported in the order of chemical shift, multiplicity (s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet and/or multiple resonance), number of protons, and coupling constant in hertz (Hz).