3- Hydroxy-1,2,4-triazine

The reaction of 1,2,4-triazine 4-oxides 55 with water in the presence of benzoyl chloride affords 3-hydroxy-1,2,4-triazines 78. The mechanism suggested for this reaction includes acylation of the substrate at the oxygen of the iV-oxide group, followed by the addition of water to the 1,2,4-tiiazinium cation and the autoaromatization of the (T -adducts with the elimination of benzoic acid. 

When one or several —CH groups are substituted for by —CO groups, the resulting compds are called oxy-, dioxy-, etc... triazines. If a —CH group is replaced by —C-OH, the compd is called hydroxy triazine (Refs 3 4)... 

Ammeline Picrate or Diamino-hydroxy-triazine Picrate, C3H5 Ns 0-QH3N307-H20, golden-yel crysts, mp 266°. It loses water of crystn only when it is heated in vacuo over P205 at 140°. Can be prepd by treating ammeline with hot coned picric acid to which some oxalic acid is added to facilitate the soln of ammeline... 

Triazines can be chromatographed as such and their GC behaviour has been studied on several stationary phases [490]. Hydroxy triazines, which are the main metabolites of triazine herbicides, cannot be analysed directly and must be converted into more volatile substances by chlorination with the aid of PC15 after prior separation of the residues of these substances in the sample [491 ]. The conversion is reported to vary in the range 75-85% at the nanogram level and the sensitivity is down to 0.03 ppm in foodstuffs with the use of the AFID. 

Aminos-triazin-2-ol. 2-Amino-4-hydroxys-triazine. 5-Azacytosine... 

N,N-diallylmelamine , vasodilator. Rat, dog, man. Extensively metabolized. N-oxidation (triazine ring, reversible reaction) to form active metabolite, then deallylation and N-reduction (rat) direct deallylation (M) (all species) hydroxylation of allyl group N-methylation (triazine ring) then deallylation UP in urine. Species difference - man does not produce active metabolite, (N-hydroxy triazine derivative). 

Tris(4-tert-butyl-3-hydroxy-2,6-dimethylben2yl)s-triazine-2,4,6-(lH,3H,5IT)trione [40601-76-1]... 

SnCl2 reduction produced the 4-hydrazinoisoxazole (243). In ethanol the diazonium salt reacted with the 4-aminoisoxazole to produce the linear triazine (244) (Scheme 85). Diazoisoxazoles can also be treated with KI or H20/urea to produce the 4-iodo or 4-hydroxy derivatives (63AHC(2)365). These Sandmeyer reactions have been extended to a variety of isoxazole systems (77JMC934, 63AHC(2)365). 

Phenanthro[l,2-d][l,2,3]selenadiazole, 10,11 dihydro- H NMR, 6, 348 synthesis, 6, 353 Phenanthro[b]thiophenes synthesis, 4, 914 Phenanthro[4,5-bcd]thiophenes synthesis, 4, 883, 907, 914 Phenanthro[9,10-ej[l, 2,4]triazines synthesis, 3, 434 Phenarsazin synthesis, 1, 561 Phenazine dyes, 3, 196-197 nitration, 3, 177 UV Spectra, 2, 127 Phenazine, 3-amino-2-hydroxy-in colour photography, 1, 374 Phenazine, 1-chloro-nucleophilic substitution, 3, 164-165 5-oxide... 

Selenazolium hydroxide, anhydro-4-hydroxy-2,3,5-triphenyl-synthesis, 6, 343 Selenazolo[3,2-b][ 1,2,4]triazine synthesis, 6, 347... 

Hydroxy butyrate dehydrogenase (from Rhodopseudomonas spheroides) [9028-38-0] Mf 85,000, [EC 1.1.1.30], amorphous. Purified by two sequential chromatography steps on two triazine dye-Sepharose matrices. [Scavan et al. Biochem J 203 699 7952.]... 

Direct bromination readily yields the 6-bromo derivative (111), just as with uracil. Analogous chlorination and iodination requires the presence of alkalies and even then proceeds in low yield. The 6-chloro derivative (113) was also obtained by partial hydrolysis of the postulated 3,5,6-trichloro-l,2,4-triazine (e.g.. Section II,B,6). The 6-bromo derivative (5-bromo-6-azauracil) served as the starting substance for several other derivatives. It was converted to the amino derivative (114) by ammonium acetate which, by means of sodium nitrite in hydrochloric acid, yielded a mixture of 6-chloro and 6-hydroxy derivatives. A modified Schiemann reaction was not suitable for preparing the 6-fluoro derivative. The 6-hydroxy derivative (115) (an isomer of cyanuric acid and the most acidic substance of this group, pKa — 2.95) was more conveniently prepared by alkaline hydrolysis of the 6-amino derivative. Further the bromo derivative was reacted with ethanolamine to prepare the 6-(2-hydroxyethyl) derivative however, this could not be converted to the corresponding 2-chloroethyl derivative. Similarly, the dimethylamino, morpholino, and hydrazino derivatives were prepared from the 6-bromo com-pound. ... 

When it was found later that enzymatic oxidation of 2-azaadenine yields its 8-hydroxy derivative (4-amino-6-hydroxyimidazo [4,5-d]-u-triazine), its synthesis was also achieved by the procedure already described/ ... 

Dichloro-s-triazine and its 6-alkyl analogs are as easily hydrolyzed by water as trichloro-s-triazine and, on suspension in aqueous ammonia (25°, 16 hr), the first is diaminated in good yield. 2,4-Bistrichloromethyl-6-methyl- and -6-phenyl-s-triazines (321) require a special procedure for mono-alkoxylation (0-20°, 16 hr, alcoholic triethylamine) disubstitution occurs at reflux temperature (8 hr). Aqueous triethylamine (100°, 3 hr) causes complete hydroxy-lation of 2,4,6-tris-trichloromethyl-s-triazine which can be mono-substituted with ammonia, methylamine, or phenoxide ion at 20°. 

The reaction of 1,2,4-triazine 4-oxides 8 bearing substituents at the 3, 5, and 6 positions with peroxyacetic acid proceeds as an N-oxidation process exclusively at the 1 position, resulting in 1,2,4-triazine 1,4-dioxides 14. Oxidation of 1,2,4-triazine 4-oxides 8 unsubstituted at the 5 position leads to 5-hydroxy-1,2,4-triazine 4-oxides 15 (76LA153). 

Triazine 4-oxides 55 react with phenols (phenol, 2,6-dimethylphenol, resorcinol, 4-hexyh esorcinol) in trifluoroacetic acid in a similar way, yielding intermediate (T -adducts 5-hydroxyphenyl-4-hydroxy-4,5-dihydro-l,2,4-triazines 61. Subsequent oxidation leads to the corresponding 5-hydroxyphenyl-l,2,4-triazine 4-oxides 62 (97MC116). 

Similarly, ring opening was found in reactions of 6-aryl-1,2,4-triazine 4-oxides 53 with aliphatic amines, yielding open-chain 6-amino-1-hydroxy- 1,4,5-triazahex-atrienes 85. In this case, however, the nucleophile adds to the 3 position of the... 

The ring-chain isomerism was studied in a series of 4-hydroxy-3,4-dihydro-1,2,4-triazines 87, which are models for cr -adducts at the 3 position of the... 

The 1,2,4-triazine 4-oxides 55 were synthesized by the reaction of nitrones 158 (generated from a-hydroxylamino ketones and aldehydes) with an excess of hydrazine, followed by the oxidation of the intermediate 4-hydroxy-2,3,4,5-tetrahydro-l,2,4-triazines 159 with lead(TV) oxide (73KGS134). 

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