Succinimidium perchlorate as a novel and efficient Brönsted acidic ionic liquid promoter for the synthesis of 5-arylidene barbituric acid and pyrano[2,3-d] pyrimidinone derivatives

In this article, succinimidinium perchlorate as a new acidic ionic liquid catalyst was prepared and used to synthesize 5-arylidene barbituric acid and pyrano[2,3-d]pyrimidinone derivatives. These two derivatives of barbituric acid have a variety of useful properties. In this article, succinimidinium perchlorate as a new acidic ionic liquid catalyst was prepared, identified and used to synthesize 5-arylidene barbituric acid and pyrano[2,3-d]pyrimidinone derivatives. The advantages of this reagent were high yields, high efficiency, short reaction times, easy performance, easy work-up and reusability. The FT-IR spectra were taken as liquid or made from KBr tablets using the Bruker PS-15 FT-IR. The vibrational frequencies absorbed were reported in cm-1.1H NMR using DMSO as solvent were recorded by a Bruker Avance NMR 500 MHz. 13C NMR spectra were recorded in DMSO using Bruker Avance NMR 125 MHz device. Tetramethylsilane was used as an internal standard. The electrothermal apparatus has been used to measure melting points in degrees Celsius. Mass spectra were performed using Agilent Technologies 5975C spectrometer via mass selective detector (MSD) operating at an ionization potential of 70 eV. Preparation of the catalysts In an ice bath, to a 50 mL round-bottom balloon containing 0.990 g of succinimide (10.0 mmol) in 20.0 mL of dry dichloromethane, perchloric acid (70%, 0.85 mL, 10 mmol) was added drop-wise over 20 minutes. After that, the mixture was stirred at room temperature for 40 minutes. At this stage, the solvent was decanted and a white solid was obtained. The precipitated product was washed 3 times with diethyl ether (3×15.0 mL) to elute the non-ionic residue. Finally, the ionic liquid was dried by vacuum apparatus and keeping in the oven at 60 ̊C for six hours . Succinimidinium perchlorate, which was made for the first time in this project, was identified with different methods, including FT-IR, 1H NMR, 13C NMR and mass spectroscopic techniques