Pyrimido indole-2,4-diones

Heating an intimate mixture of bis(2,4,6-trichlorophenyl)malonate and the appropriate 3-aminotriazinoindoles 657 afforded pyrimido-[3, 2 2,3][ 1,2,4]triazino[5,6-fe]indole-2,4-diones 658 (88JHC475). 

Carboxy substituted diazepines 226 and 229 react with phenyl isocyanate to afford pyrimido diones 227 and 230, correspondingly (Scheme 48, Section 3.1.1.3 (1993JHC897)). N-Hydroxymethylation on an indole ring annulated to benzaze-pinone, as well as formation of the corresponding carbamate and urea, has been described (2004MI1076). 

On irradiation with a high-pressure mercury lamp, 9-phenyl-8-azapurine in dioxane gave 9i/-pyrimido[4,5-i>]indole in 33% yiel whereas 54% was obtained in methanol. Nine derivatives of this azapurine, carrying various substituents in the 6 position, behaved similarly (32-91% yields). The principal by-products arose from (1) replacement of hydrogen in the 4 position of the pyrimidoindole by dioxane or methanol residues, (2) reaction with benzene, when used as a solvent, to yield 4-anilino-5-phenylpyrimidine, and (3) reaction with dioxane to furnish 4-anilinopyrimidines. l,3,7-Trimethyl-8-azapurine-2,4-dione, irradiated with diethylamine in acetonitrile, gave 6-diethylamino-1,2-dimethyl-5-methylaminopyrimidine-2,4-dione (66% yield). However, photolysis in methanol gave 5-hydroxy-l,3-dimethyl-6-methoxypyrimidine-2,4- one (22% yield). 

Pyrimido(4,S-Jb [l,4]diazepin 4-one. 977 Pyrimido[l,2-6iind le. 1004 Pyrimido(l,2-aliiidole. 1329 I rimido[l,6-[Pg.778]

In a similar way, pyrimido[4,5-< ][l,2,4]triazin-6,8-diones, bearing the alkylsulfonyl group, undergo the nucleophilic displacement reaction by action of malonodinitrile, indole, and l-phenyl-3-methyl-5-pyrazolone <1998RJ0297, 2003KFZ20, 2003PCJ238>. 

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