Synthesis of new (trifluoromethyl)-1H-benzo[e][1,2,4]triazolo[1,2-a] [1,2,4]triazine-1,3(2H)-diones and (trifluoromethyl)benzo[5,6][1,2,4] triazino [1,2-b]phthalazine-8,13-diones

In this paper we investigated reactions of urazole and phthalazine with N-(aryl)-2,2,2-trifluoroacetimidoyl chloride derivatives. Results showed that when imidoyl chloride derivative has a fluorine atom at ortho position (3a-c), in two steps under a S(N)i mechanism and then SNAr reaction mechanism produce ay1-5-(trifluoromethyl)-1H-benzo [el [1,2,4]triazolo[1,2-a] [1,2,4]triazine-1,3(2H)-diones (4a-c) and 6-(trifluoromethyl)benzo[5,6][1,2,4]triazino[1,2-b]phthalazine-8,13-diones (4i,4j) in good to excellent yields. In the other imidoyl derivatives (3d-h and 3i,3j) under these conditions cyclization reaction does not occur and therefore produce 1-aryl-2,2,2-trifluorornethyl)-4-phenyl-1,2,4-triazolidine-3,5-diones (4d-h) and 2-(2,2,2-trifluoro-1-(arylimino)ethyl)-2,3-dihydrophthalazine-1,4-diones(4k,41) (non-cyclic products) in good to excellent yields. (C) 2016 Elsevier B.V. All rights reserved.