SYNTHESIS AND REACTIONS OF 3-AROYL DERIVATIVES OF 4-HYDROXY-2-QUINOLONES AND 4-HYDROXYCOUMARIN

3-Aroyl-4-hydroxy-2-quinolones 4 and 11 can be synthesized starting wi th 1 or 9 via Fries rearrangement of the corresponding esters 3 and 10 , catalyzed by potassium cyanide and 18-crown-6. A one pot procedure i s presented in which the esters do not need to be isolated. Reduction of the aryl ketones 4 and 11 with zinc dust leads to the benzyl deriva tives 5 and 12. Reaction of the aryl ketones 4 and 11 with hydroxylami ne and subsequent heating of the crude product leads via thermal Beckm ann rearrangement and dehydration to oxazoloquinolones 7 and 14. 2-Aro yloxypyrido[1,2-a]pyrimidin-4-ones 17 and 20 could not be converted to the corresponding ketones by Fries rearrangement.