Synthesis of N phenylsuccinimide-D2

N phenylsuccinimide labeled with deuterium was necessary as internal standard in the GC-MS quantitative analysis. The N phenylsuccinimide was labelled with deuterium by catalytic hydrogenation of N phenyl maleinimide. The N phenyl maleinimide was obtained by condensation of aniline with maleic anhydride in anhydrous pyridine. The crude obtained imide was purified by two recrystallizations in cyclohexane. The purified product was analyzed by melting point determination and thin layer chromatography, using chromatographic system: silicagel GF254 as substrate and benzene: methanol (4:1) mixture, as eluent. The deuterium labelled compound was obtained by hydrogenation of N phenyl maleinimide in anhydrous hexane, in presence of Pd/BaSO4 (10%) as catalyst and D2 gas at 500 torr. The conversion reaction was followed up using a manometer. Reaction time was 1 hour. The catalyst was separated from reaction mixture by filtration and the solvent was evaporated using a rotavapor. Unlabelled imine was synthesized using a similar method. The obtained raw products were purified by recrystallization from methanol. Labelled and unlabelled products were analyzed by melting points determination, IR, UV VIS, NMR spectroscopy and GC-MS. The IR spectra of N phenylsuccinimide D0 and D-2 were simulated using chemical quantum methods and results were compared with experimental spectrum. Quantum chemical calculations (vacuum approximation) were carried out using the Hyperchem 7 software. N phenyl succinimide D0 and D2 were built and geometrically optimized using periodic box molecular mechanics (MM+), followed by semi empirical methods (PM3 and AM1). The IR spectra were simulated using 'Vibrational spectrum' Hyperchem facilities. Significant isotopic effects were identified in the IR spectra. (author)