Einfluß von Lösungsmittel und Halogenessigsäure auf die Fluorescenz von N-Aryl-anthranilsäuren und verwandten Verbindungen

The influence of a pretreatment of flufenamic acid and other N-aryl-anthranilic acids by alkaline saponification and oxidation, as well as the influence of the solvent and the added halogenoacetic acid on fluorescence intensity has been investigated. Derivatives of the flufenamic acid (e.g. esters or amides) must first be hydrolyzed. To render the solution fluorescent solvents with a DK = 0 are required. The halogeno-acetic acids (e.g. mono-, di-, trichloro-, -bromo- and -fluoroacetic acids) with a pK_a-value <1 are suitable. Acids with a pK_a-value >1 are completely unsuitable. Arylsubstituation influences the position of the fluorescence maxima but not the intensity. Anthranilic acid itself shows fluorescence in chloroform-trichloroacetic acid while their m- and p-analogues as well as diphenylamine do not.