phthaleins

In a series of masterly experiments von Baeyer demonstrated several years ago the chemical nature of the phthaleins and showed that, just like the already known rosaniline dyes, they may be classified as derivatives of the hydrocarbon triphenylmethane.

Nobel Prize in Chemistry 1905 - Presentation Speech 1966

The stimulus was given by his discovery of a new group of beautifully coloured compounds, the so-called phthaleins, of which only the eosin pigments, highly important to industry, and the rhodamin dyes derived from them, may have particular mention here.

Nobel Prize in Chemistry 1905 - Presentation Speech 1966

Studies were initiated on condensation reactions which, after Baeyer had gone to Strassburg as Professor in the newly established University (1871) brought to light that important category of dyestuffs - the phthaleins.

Adolf von Baeyer - Biography 1966