Triaza-Compounds

Triaza-compounds. 1,1,1,-Trifluoroacetylacetone condenses with cyano-acetylhydrazine to give a mixture of the pyridone (790) and the pyrazolopyridine (791). Thermolysis of the azide (792) leads to the rearranged pyrrolopyridaz-inone derivative (793). The complex heterocycle (796) is the unexpected product of the reaction of 4,5-diaminopyrimidine (794) with benzo-cyclobutanedione (795)/  

Diaza- and Triaza-Compounds. The photochemical rearrangement of the flnfi- bimane (541) to the fused oxazinone (542) has been reported.  

4-Aryl-3,5-dihydroxypyrazoles (543) condense with acetylacetone to afford the novel paraionic 87r-betaines (544). The isomerization (545) - (546) has been observed. The urazole (547) adds the thioketen NCPhC=C=S to form the heterocycle (548). Dye-sensitized photo-oxygenation of the pyrazolo[l,2-a]benzotriazole (549) yields mainly the epoxide (550). °  

Capuano, F. Braun, J. Lorenz, R. Zander, and J. Bender, Liebigs Ann. Chem., 

Albini, G. F. Bettinetti, G. Minoli, and G. Vasconi, J. Chem. Soc., Chem. 

Other work on aza-compounds will be found in references 608-616. 

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Triazanaphthalenes (446) substituted with a single leaving group have been little studied. 4-Aminopyrido[3,2-d]pyrimidine and its 6-methyl derivative have been hydrolyzed with 5N acid (100°, 30 min) and lOA alkali (95°, 3 hr, 10% yield).Attempted replacement of the 4-oxo group (via acyloxy intermediates) with phosphorus oxychloride or pentasulfide failed,in contrast to the successful replacement in the more activated 4-oxo-l,3,8-triaza analog discussed below. Similarly, the 2,4-dioxo derivative could not be thionated with the pentasulfide, and its reaction with the oxychloride was less facile than that of the 2,4-dioxo-l,3,8-triaza compound. 

Triaza-Compounds. 2-(Ethoxymethyleneamino)pyridine is converted into the triazolopyridine (564) by the action of hydroxylamine-O-sulphonic acid. Anodic oxidation of the hydrazone Ar NHN=CHAr (Ar =p-NO2C6H4, Ar = /7-MeC6H4) in the presence of pyridine and tetraethyl-ammonium perchlorate affords the salt (565). Oxidative cyclization of the pyridylhydrazone PyCH=NNHPy (Py = 2-pyridyl) by means of mercury(II) acetate yields compound (566). 2,4,6-Triphenylpyrylium fluoroborate reacts with amidrazones ArC(NH2)=NNH2 in the presence of triethylamine to give the pyrazolopyrimidines (567). The tricyclic compound (568) is... 

Triaza-Compounds. 4,5-Dicyanoimidazole (495) adds methyl isocyanate to yield the imidazoimidazole (496), which in turn adds phenyl isocyanate, giving the tricyc-... 

Monoaza-Compounds 273 Diaza-Compounds 273 Triaza-Compounds 273... 

Monoaza-Compounds 276 Diaza-Compounds 276 Triaza-Compounds 276 Tetra-aza-Compounds 279 Mixed Oxygen-Nitrogen Systems 279... 

Triaza-compounds. Triazolium ylides (714) yield the 1,3-dipolar cyclo-adducts (715 R = C02Me or CN) with methyl acrylate or acrylonitrile. 6-Methyl-imidazo[l,2-Z>]pyrazole (716) is methylated at N-5 but acetylated at N-1. ... 

The principal approach to build the 1,2,4-triazine ring is condensation of 1,2-dioxo derivatives or their synthetic equivalents (for instance, a-keto esters or a-keto substituted nitriles) with 1,2,4-triaza compounds, such as thiose-micarbazides or amidrazones. Indeed, the first synthetic route to lamotrigine is based on a direct condensation of 2,3-dichlorobenzoyl cyanide with aminoguanidine (Scheme 193) . Disadvantages of the method are... 

Only two types of azawurtzitanes are known, 3-aza- and 3,5,12-triaza compounds. The parent hydrocarbon wurtzitane (22, also called iceane) was first synthe ed by Cupas and Hodakovs ki in 1974 (Ref. 86a) its... 

Iodine-sodium/alcohol Hofmann degradation of semicarbazones 1,2,3-Triaza compounds... 

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