Reactions of 1,2,4-triazin-5(2H)-ones with phenols and aromatic amines

1,2,4-Triazin-5(2H)-ones 1 react as well with phenols, resorinol and its dimethyl ethers, as with dimethyland diethylaniline, yielding 6-aryl-1,6-didydro-1,2,4-triazin-5(2H)-ones 2, 4–8, 12–15. Oxidation of the 1,6-dihydroadducts 2a,b gives the corresponding 3-aryl-6-hydroxyphenyl-1,2,4-triazin-5(2H)-ones 3a,b. Rection of 1,2,4-triazinones 1 with 2-naphthylamine leads to destruction of the 1,2,4-triazine ring yielding benzoe]indole-2,3-dione 19.