Vinylogous acyl compounds. XV. Thin-layer chromatographic detection of 2-halovinyl ketones with toxicological relevance (author's transl)]

The basic ring-opening of 1-(2-acylvinyl)-pyridinium salts yielding azaoxonol dyes and the spontaneous dehydrohalogenation of 1-(2-acylvinyl)-4-(4-nitrobenzyl)-pyridinium salts to deeply coloured anhydrous bases underlie two sensitive thin-layer chromatographic detection procedures for 2-halovinyl ketones (R-CO-CH=CH-X). The detection limits are 0.06 mug on successive use of methanolic solutions of pyridine and potassium hydroxide as spray reagents and 0.02 mug on spraying with an acetonic solution of 4-(4-nitrobenzyl)-pyridine. RF values of twenty-five trans- and twelve cis-configurated 1-halovinyl ketones for three solvent systems are given.