6317-85-7Relevant articles and documents
An eco-friendly method for synthesis of symmetrical and unsymmetrical benzoin derivatives
Safari, Javad,Arani, Naimeh Moshtael,Isfahani, Anousheh Ramezan
experimental part, p. 495 - 498 (2011/12/21)
A rapid, highly efficient and mild green synthesis of symmetrical and unsymmetrical benzoin derivatives was achieved from the reaction of benzaldehyde derivatives with potassium cyanide in dimethyl sulfoxide under argon gas and ultrasound. This simple method affords benzoin derivatives at room temperature in short reaction times with high yield and purity.
Influence of protonation of peripheral substituents on photophysical and photochemical properties of tetrapyrazinoporphyrazines
Novakova, Veronika,M?rkved, Eva H.,Miletin, Miroslav,Zimcik, Petr
experimental part, p. 582 - 591 (2011/10/03)
Octasubstituted zinc tetrapyrazinoporphyrazines with four N,N-dimethylaminophenyls and four phenyl or pyridin-3-yl substituents were synthesized and fully characterized. Their fluorescence quantum yields in DMF or pyridine were very low, almost undetectable, as a consequence of ultrafast intramolecular charge transfer. Titration of their DMF solutions with sulfuric acid led to increase of the fluorescence quantum yields by two orders of magnitude when the full protonation of peripheral substituents was achieved. Intramolecular charge transfer is no longer a favorable way of excited-state relaxation at full protonation of N,N-dimethylaminophenyl substituents because of loss of donor centers (free electron pair on its nitrogen). Similarly, singlet oxygen quantum yields also increased by two orders of magnitude when sulfuric acid was added to tetrapyrazinoporphyrazine solutions in DMF. Protonation at azomethine nitrogens of tetrapyrazinoporphyrazine macrocycle was observed at higher acid concentrations and it led to considerable decrease of fluorescence quantum yields. Octaphenyl zinc tetrapyrazinoporphyrazine and octa(pyridin-3-yl) zinc tetrapyrazinoporphyrazine were used as controls without intramolecular charge transfer. Their fluorescence and singlet oxygen quantum yields were high in DMF and decreased at higher concentrations of sulfuric acid due to protonation of azomethine nitrogens. The results suggest that the photophysical and photochemical properties of studied compounds may be controlled by changes of pH of medium.
One-pot synthesis of phenytoin analogs
Mahmoodi,Emadi
, p. 377 - 382 (2007/10/03)
A series of phenytoin analogs (5,5-diphenylimidazolidine-2,4-dione or 5,5-diphenyl-hydantoin) were synthesized in 65-75% yield from the corresponding substituted benzils. The same products were also obtained directly from α-hydroxy ketones via one-pot procedure.
