4-Alkyl-alkanoyl-7-hydroxy-coumarin prepn. in good yield - by alkanoylating corresp. unsubstituted cpd. using Friedel-Crafts catalyst

摘要

4-Alkyl-6 (or 8)-alkanoyl-7-hydroxycoumarins of formula (I):- (where R is unsubstd. alkyl; and R1 is alkanoyl ortho to the 7-OH) are prepd. by reacting a corresp. 4-alkyl-7-hydroxycoumarin (II) with an alkanoylating agent in presence of a Friedel-crafts catalyst. Good yields of (I) in a simple process compared with the previously used Fries rearrangement; (I) are intermediates for pharmacologically active cpds.