Synthesis of 4-Aminocoumarin Derivatives with N-Substitutents Containing Hydroxy or Amino Groups

Reactions of 4-hydroxycoumarin (1a) and 4-chlorocoumarin-3-carbaldehyde (1b) with amino alcohols or alkylene diamines led to the formation of the corresponding N-substituted 4-aminocoumarins 3, 5 and 6. However, 4-hydroxycoumarin-3-carbaldehyde (8) reacted with 2-aminoethanol and ethylenediamine to give N-substituted 3-(aminomethylene)-chromane-2,4-diones 9a, b. The structure and the E-configuration of compound 6 were proven by X-ray crystal structure analysis. Products 9a, b displayed signals of both E- and Z-isomers in their NMR spectra. All novel products have been characterized by means of spectral (IR, NMR, MS) data and elemental analyses.