Syntheses of a Series of Fluorescent Carboxylic Acids with a 1, 3-Benzodioxole Skeleton and Their Evaluation as Chiral Derivatizing Reagents

A series of fluorescent carboxylic acids with a common skeleton of 1, 3-benzodioxole-4- or 5-carboxylic acid were prepared as racemates or in an optically active form. Their potential as chiral derivatizing agents was evaluated in terms of the HPLC and 1H-NMR analyses of D, L-amino acids. Every acid with a carboxyl group at C-4 showed high separation ability of original enantiomers in both the HPLC and the NMR analyses, while the C-5 isomer showed little separation. As the difference in the bulkiness between the two substituents at C-2 became wider, the separation by HPLC increased. These studies allowed us to develop new chiral reagents useful both for HPLC and 1H-NMR analyses, along with our previous reagent, (S)-TBMB carboxylic acid.