El 3

All chemical were purchased from the Merck, Sigma-Aldrich, and used without further purification. Solvent were dried and distilled prior to use. Merck pre-coated silica gel plates with a fluorescent indicator were used for analytical TLC. Flash column chromatography was performed using silica gel (Merck). Ethyl acetate – hexane was used as a eluting solvent for TLC and column chromatography. Melting points were recorded in open capillary tubes and were uncorrected. The FT-IR spectra (KBr) were recorded on a Shimadzu 8201pc (4000–400 cm⁻¹) spectrometer. The ¹H NMR (Proton Nuclear Magnetic Resonance Spectra) were obtained on a Bruker DRX-300 MHz and those of ¹³C NMR (Carbon Nuclear Magnetic Resonance Spectra) were recorded on a Bruker DRX-75 MHz advance spectrometer. Chemical shifts of ¹H and ¹³C Nuclear Magnetic Resonance spectra were expressed in ppm in downfield from tetramethylsilane. Mass spectrum (EI) was recorded on a Jeol JMS D-300 spectrometer operating at 70 eV. The elemental analysis (C, H, N, and S) were recorded using an Elemental analyzer model (Varian EL III) and agreed with the calculated values.

All the chemicals were synthetic grade and commercially procured from Sigma Aldrich. The melting point was determined in an open capillary tube and it is uncorrected. The IR spectra were recorded in KBr on a shimadzu 8201pc (4000–400 cm⁻¹). The ¹H NMR and ¹³C NMR spectra were recorded on a Bruker. The elemental analysis (C, H and N) was recorded using an elemental analyzer model (Varian EL III). The purity of the compounds was checked by thin layer chromatography (TLC) with silica gel plates.