Synthesis of 2-methyl-4-selenoquinazolone, 2-phenylbenzoselenazole, and its derivatives / Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Faculty of Pure Science of Columbia University

by Yü-Gwan Chen

Analysis of Selenium Organic Compounds

In the quantitative determination of selenium in quinazoline the method adapted by Becker and Meyer was found to be quite satisfactory[(56)]. Other methods are listed in the bibliography[(57)].

In the ultimate analysis of carbon and hydrogen, the ordinary absolute method was followed with the use of copper oxide, lead chromate, and lead peroxide in the tube. In the determination of nitrogen the ordinary absolute method was also followed excepting that a considerable quantity of specially prepared lead chromate powder was mixed with the sample in a number six porcelain boat. This was found to be desirable when the dinitroselenazole was burned. Selenium dioxide, which is a solid, seems to be formed in the tube and carried away by the current of carbon dioxide with some difficulty. In such a case the analysis usually took four hours after the combustion had actually started. In the carbon and hydrogen determination selenium dioxide was easily absorbed in the presence of oxygen gas.