SYNTHESIS OF CYANINE DYES BY THE CONDENSATION OF p-DIETHYL- AMINOBENZALDEHYDE WITH APPROPRIATE HETEROCYCLIC COMPOUNDS. PART I

Three new dyestuffs have been obtained by the condensation of p-diethylarninobenzaldehyde with the ethiodides of lepidine, p-toinquinaldine and 6-ethoxyquinaldine. One of these compounds, the p- toluquinaldine condensation product has been found to be a powerful sensitiser which can be commercially uti­lised. unlike other cyanine dyes, these substances dye silk and wool in fast colours. The flourescence and other characteristics of these dyes have also been examined and recorded.