Abstract 7-Hydroxycoumarins 4 with a 2-, 3-or 4-pyridyl substituent in position 3, their ethers (3), esters (5, 6), and quaternized derivatives (7–9) have been synthesized by a generally applicable method starting from 2-hydroxy-4-methoxybenzaldehyde (1). The absorption and fluorescence spectra in methanol and water of different pH values are reported, and the effects of substituents on spectra and pK a values are discussed.
