Hydantoins sulfur compounds

The use of ligand exchange has been examined for the analysis of PTH (phenylthio-hydantoin) amino acids separated on silica gel plates [92]. The method is an extension of the procedure developed for organophosphate pesticides [84]. The chromatoplate is sprayed with a solution of palladium(II) chloride and calcein. Palladium complexes with calcein to form a non-fluorescent chelate. However, in the presence of many sulfur-containing compounds, such as PTH-amino acids, the palladium is displaced from the complex liberating free calcein which gives an intense fluorescence. This method is capable of determining 0.1-nmole amounts of PTH-amino acids. 

Amino-3-carboxy-l-propyl Methyl Tellurium1 In a Teflon-lined bomb are placed 40 mg (0.15 mmol) of 5-(/)-methyltelluroethyl)-hydantoin and 1 ml of 1 M aqueous sodium hydroxide solution. The mixture is heated at 165° for 1 h and then cooled. The solution is carefully acidified with 10% aqueous sulfuric acid, filtered, and the filtrate is lyophilized. The product, a tan-colorcd solid, is a mixture of the desired compound with inorganic salts which is not further purified. 

Photoelectron spectroscopy has demonstrated that there is no linear correlation between the ionization energies and p values of azoles <84JHC269>. The gas phase photoelectron spectra of a series of hydantoin derivatives (32) have been compared with those of model compounds, and with the results of HAM/3 and CNDO/S calculations. Evidence is found for significant interactions between the 7r-orbitals and the chalcogen atoms for sulfur and selenium derivatives. In contrast, n-orbitals of the nitrogen atoms are localized in the whole series of compoimds, especially in the oxy analogues and in monosubstituted derivatives <88JST(175)447>. 

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