Preparation of amino acid anthraquinone oxalamide derivatives as colorimetric sensors for detection of the fluoride anion in solution and gel.

The invention relates to oxalamide derivs. of anthraquinone with general formula I [R1 is C1-6 alkyl, Ph, benzyl, or p-hydroxybenzyl; R2 is H, C1-6 alkyl, benzyl, or M+; X = (CH2)1-9] and their optical isomers and their mixts., including their prepn. and use for binding fluoride anions in soln. and gel, causing a change in color of the soln. and change in color and morphol. of the gel (phase change from gel to liq.). Thus, I (R1 is L-leucine side chain; R2 is Me; X is CH2) was prepd. by reactions of oxalyl chloride, L-leucine Me ester hydrochloride, N-benzylethylendiamine, and ethyl-N-1-anthraquinone oxamate and shown to bind fluoride anion, but not chloride, bromide, or iodide anions.