. . . . . . . . "illicit"@en . . . . . . . . . . . . . . . . "Akinori Fujita, \"Phenylurethane compounds and methods for producing same, asymmetric urea compounds and methods for producing same, barbituric acid derivative, and diazo thermal recording material containing the derivative.\" U.S. Patent US20020161225, issued October 31, 2002."@en . . . . . "Barbituric acid derivative"@en . . . "experimental"@en . . . . .