N-CHLOROMETHYLPHTHALIMIDES AS DERIVATIZATION REAGENTS FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A new class of substances is described. the N-chloromethylphthalimides, which can be used as UV-sensitive reagents for the formation of derivatives suitable for high- performance liquid chromatography (HPLC). The highly reactive chlorine in the N-methyl group reacts quantitatively with alkali metal or ammonium salts of CH-, OH- and NH-acid compounds. The salts of the free acids can be formed by direct addition of triethylamine to the reaction mixture. Hence the reagents is suitable for fast pre-column derivatization of free acids. Aprotic solvents are suitable reaction media. Acetonitrile is used with preference, as the reaction solution does not absorb at 254 nm and can be analysed directly by usng HPLC. If a crown ether is used as a phase transfer catalyst, alkali metal salts of carboxylic acids can be quantitatively converted within 15 min at 60°. The application of this group of reagents in derivatization are illustrated by examples of mono- and dicarboxylic acids and barbiturates. © 1979.