Method of manufacture of biologically active coumarin derivatives

摘要

3,31 - Bis - 4 - hydroxycoumarinyl - acetone is prepared by condensing 4-hydroxycoumarin with an asymmetric dihaloacetone, e.g. dichloro-or dibromo-acetone. Examples are given in which the condensation takes place by refluxing dichloro- or dibromo-acetone with an aqueous suspension of 4-hydroxycoumarin which has been neutralized to Methyl Red by means of caustic potash. Specification 672,357 is referred to.