Triazo Compounds

Azido or Triazo- Compounds, contg one or more N3 groups, are the org derivatives of hydrazoic acid, HN3. These compds are usually unstable to heat and often decompose violently. They may be divided into four classes ... 

Triazoates. See Azides, Inorganic A520-L Triazo Compounds. See Azido Compounds A626ff... 

This triazo compound is a derivative of the interesting nitrogen-hydrogen acid, N3H, hydrazoic or triazoic acid, (p. 64). 

To date little is known about the chemistry of triazocines. Only three of the five possible isomeric structures are relevant in the context of this review as there are no reported syntheses of the 1,2,3- (I) and 1,3,6-triazo (5) compounds. A special review on triazocines is available.1... 

Treatment of 3-diazo-3//-[ 1,2,4]triazole with 1-morpholinocyclohexene or 1-piperidinyl cyclohexene gave triazolotriazine 818 (87JOC5538), and with 1,1-dimethoxyethane afforded a mixture of two isomers of triazolo[3,4-c]triazine 819 and triazo)o[5,l-r]triazine 820, respectively [90JCS(P2)1943]. Compound 819 was the major product and it converted on storage to 820 (Scheme 165). 

Many dyes are decolorized and ultimately mineralized by photocatalysis. In the degradation of azo dye,18 21) the degradation rate decreases in the order monoazo > diazo > triazo.1819) Three processes including oxidation and reduction are considered to occur simultaneously in the photocatalytic degradation of dye. These are illustrated in Fig. 9.9. Process 1 is the common photocatalytic degradation process of organic compounds. Process 2 is spectral sensitization as observed in a wet-type solar cell. In process 3 one moiety of dye molecule serves as the electron acceptor, suppressing recombination between electron and positive hole. 

The preceding compound (5 grams) is warmed with 12 grams of di-methylaniline a blue condensation product separates out. This is dissolved in 20 c.c. of hot acetic acid, the solution filtered and the filtrate treated with ether, when the required dye separates in blue flocks. If the dinitroso-com2)ound is reifiaced by 3-nitro-4-triazo-phenylarsinic acid, the same product is obtained. The dye is very sjjaxingly soluble in water, ether, and benzene, moderately soluble in sodium carbonate, readily soluble in alcohol, acetic acid, and sodium hydroxide. 

Compound (VII) can be further transformed to triazo-lones, useful building blocks for pharmaceuticals such as Etoperidone or Nefazodone (see cyclisation between two nitrogen atoms, next section). In the case of Etoperidone, this transfomation avoids the use of toxic ethyl isocyanate to get the required intermediate as shown in scheme 203. 

Diels-Alder and ene reactions of singlet oxygen, nitroso compounds, and triazo-linediones 02CC1243. 

The chemistry of short-lived intermediates is difficult to study because usually the species cannot be directly observed under the reaction conditions. Much of the knowledge is therefore obtained by deduction from product studies. In the present review we are dealing mainly with intramolecular gas-phase reactions, and the carbenes and nitrenes in question are most frequently generated from diazo-compounds and azides (or in heterocyclic systems valence isomers thereof, triazo-loazines and tetrazoloazines). It is known that diazo-compounds and azides deld carbenes and nitrenes, respectively, by low-temperature photolysis i>2). However, the cycloheptatrienylidenes and azepinylidenes invoked in many reaction mechanisms have not yet been observed by any spectroscopic means, and their existence is deduced exclusively from their chemistry. 

Two new model compounds derived via reaction of 22 ith methyl triazo-... 

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