Gemini 300

The reactions were started by available samples. 5-Amino- and 5-methyl-substituted 1, 3, 4-thiadiazole-2-thio acyl derivatives were synthesized independently. 0.01 Mol of each reactant, 0.01 mol of potassium carbonate, and 20 ml of dry acetone were refluxed in 100 ml RBF on oil bath for three hours. The progress of the reaction was monitored by TLC using an appropriate mobile phase. After the reaction was completed, excess of dry acetone was distilled off, and after cooling, the reaction mixture was poured in ice cold water. Then, the product was purified by crystallization and column chromatography. The melting points of the compounds were determined on a Böetius PHMK apparatus (Veb Analytik, Dresden, Germany). The TLC was performed using aluminum plates, precoated with silica gel 60 or 60 F254 (Merck, Munchen, Germany), and visualized by UV light (254 nm, Merck, Darmstadt, Germany). The NMR spectra were recorded on a Varian Gemini 300 and Bruker DRX 400 spectrometer (Varian, Palo Alto, CA, USA) at 25°C. The IR-spectra were recorded (KBr) on a Jasco FT/IR-410 instrument (Jasco, Easton, PA, USA) [22 (link), 23 ].

Optical rotation was measured using an auto digital polarimeter, and Fourier transform infrared (FT-IR) spectra were recorded using Nicolet 380 FT-IR spectrophotometer (Thermo Electron Corporation). Nuclear magnetic resonance (¹H NMR and ¹³C NMR) spectra were obtained using Varian Gemini 300 (300, 75 MHz) and Bruker Avance 500 (500, 125 MHz) using tetramethylsilane as internal standard. Low-resolution mass spectrometry profiles were obtained using a JEOL the MStation JMS-700. Chiral high-performance liquid chromatography (HPLC) analysis was performed using a Jasco LC-1500 Series HPLC system. Toluene (CaH₂), tetrahydrofuran (THF) (Na, benzophenone), and CH₂Cl₂ (CaH₂) reaction solvents were purified before use. The reagents used in this study were obtained from Aldrich, Acros, Alfa, Sigma, Merck, Fluka, TCI, and Lancaster, and purified or dried using a known method when necessary. Merck’s silica gel 60 (230–400 mesh) was used as the stationary phase in column chromatography.