Purification and Characterization of Compounds

All chemicals and reagents were purchased from Sigma-Aldrich, Acros, Avera Synthesis, Spectrochem Pvt. Ltd., and used without further purification. Commercially available anhydrous solvents (THF, DMF, benzene, toluene, MeOH, EtOH, and CH₂Cl₂ Spectrochem) were used in the reactions. Thin-layer chromatography (TLC) was performed using precoated aluminum plates purchased from E. Merck (silica gel 60 PF254, 0.25 mm). Column chromatography was performed using Spectrochem silica gel (60–120 mesh). Melting points were determined in open capillary tubes on the Precision Digital melting point apparatus (LABCO make) containing silicone oil, and the results are uncorrected. IR spectra (neat) were recorded on an Agilent FTIR spectrophotometer. ¹H and ¹³C NMR spectra were recorded either on an Avance III Bruker or a JEOL JNM-ECS spectrometer at operating frequencies of 200/400/500 MHz (¹H) and or 100/125/150 MHz (¹³C) as indicated in the individual spectra using TMS as an internal standard. Elemental analyses were performed on a Carlo-Erba 108 or an Elementar Vario EL III microanalyzer. The room temperature varied between 25 °C and 30 °C. The multiplicities in the ¹HNMR spectra are presented as s for singlet, d for doublet, dd for doublet of the doublet, td for a triplet of doublet, t for triplet and m for multiplet. The multiplicity in the ¹³C NMR spectra is presented as d for doublet.