摘要:
The title reactions give 1-hydroxy-4-methylquinoxaline-2,3-diones (4) together with a variety of mono- and bi-cyclic by-products All of these may result from a common intermediate, viz. a 1-hydroxy-4-methyl-3,4-dihydro-1H-2,1,4-benzoxadiazine-3-carboxylate ester (18).