REACTIONS OF 2-METHYL-3,1-BENZOXAZIN-4-ONE WITH ACTIVE METHYLENE-COMPOUNDS - A NEW ROUTE TO 3-SUBSTITUTED 4-HYDROXYQUINOLIN-2(1H)-ONES

A new route to 3-substituted 4-hydroxyquinolin-2(1H)-ones, compounds o f great biological importance, is described. The C-acylation of active methylene compounds 2 with the 2-methyl-3,1-benzoxazin-4-one 1, under basic conditions, leads to the formation of the new products 3-10, wh ich have been isolated and characterized. Cyclization of the above int ermediates furnishes the 3-substituted 4-hydroxyquinolin-2(1H)-ones. S pectral data and physical characteristics for all compounds are report ed.