Abstract The reactivity of variably substituted 2-methyl-4H-3, 1-benzoxazin-4-ones and 2- methyl-4H-pyrido [2, 3-d][1, 3] oxazin-4-one towards carbon and oxygen nucleophiles under microwave irradiation conditions was investigated. Optimization of the reaction conditions of oxazinones with carbon nucleophiles led to the synthesis of a series of 4-hydroxy-quinolin-2- ones and 4-hydroxy-1, 8-naphthyridin-2-ones in high yields, whereas reaction with a ...