10.1080/10426500701340949
The research focuses on the preparation of new tert-butyl substituted coumarins, thiocoumarins, and dithiocoumarins. The study was motivated by the researchers' interest in these compounds for their investigations on the EPR spectra of ester, thioester, and dithiopyrone radical anions. The researchers synthesized various compounds, starting from tert-butylphenols and diketene to prepare 6-tert-butyl-4-methylcoumarin and 6,8-di-tert-butyl-4-methylcoumarin via aryl acetoacetates. Thionation of these coumarins with Lawesson's or Davy's reagent led to the formation of the corresponding thion- and dithiocoumarins. Key chemicals involved in the research include 4-tert-butylphenol, 2,4-di-tert-butylphenol, 4-tert-butylthiophenol, diketene, sulfuric acid, aluminum trichloride, and various reagents for thionation such as Lawesson's reagent (2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 1,3-disulfide) and Davy's reagent (2,4-bis(methylthio)-1,3,2,4-dithiadiphosphetane 2,4-disulfide). The structures of the synthesized compounds were confirmed using NMR spectroscopy and X-ray structure analysis.
10.1073/pnas.18.7.490
The research investigates the chemical properties and transformations of isovioluric acid and its derivatives. The purpose of the study is to explore the behavior of isovioluric acid, an unusual oxime of alloxan, and its reduction products. Key chemicals involved include isovioluric acid (VI), which is derived from isobarbituric acid through the action of nitrous acid. This compound exhibits unique properties such as oxidation of potassium iodide and formation of colored salts. The study also examines the reduction of isovioluric acid to isouramil (XI) using ammonium sulfide, which resembles dialuric acid in its chemical properties and can be converted into dialuric acid (XII) by hydrochloric acid. The research concludes that isovioluric acid and its derivatives display distinct behaviors compared to related compounds like alloxan and violuric acid, providing new insights into the chemistry of these uracil derivatives and their potential applications in the study of purine group compounds.
Xn,
N
Xn:Harmful;
