5- Hydroxyphenyl-1,2,4-triazine 4-oxides

Triazine 4-oxides 55 react with phenols (phenol, 2,6-dimethylphenol, resorcinol, 4-hexylresorcinol) in trifluoroacetic acid in a similar way, yielding intermediate (T -adducts 5-hydroxyphenyl-4-hydroxy-4,5-dihydro-1,2,4-triazines 61. Subsequent oxidation leads to the corresponding 5-hydroxyphenyl-1,2,4-triazine 4-oxides 62 (97MC116). 

A reaction of benzyne with the 6-unsubstituted 1,2,4-triazine-l-oxides 58 (R1 =Ph, R2 = H, Me) gave the 1,3-benzoxazepines 59 (R1 Ph, R2 = H, Me) (15-20% yield) and the 6-(t>-hydroxyphenyl)-l,2,4-triazines 60 (30-40% yield) via the (C6NO)-l,3-dipolar cycloadducts (Equation 14) <1996H(43)2091>. From the cycloadduct, sequential N-O bond cleavage, a 1,3-shift, and nitrogen loss provided access to 59 a competing 1,5-shift, followed by aromatization, led to the alternative products 60. 

The (7 -adducts 110 derived from the reaction of 3-aryl-l,2,4-triazin-5(2//)-ones 34 with 2,6-dimethylphenol in TFA can be characterized by H NMR however, if potassium hexacyanoferrate is added to the reaction mixture, the adducts 110 are transformed into 3-aryl-6-hydroxyphenyl-l,2,4-triazin-5-ones 111 (Scheme 59) <97JHC537>. In addition, the reaction of 34 with anisole on reflux in TFA affords 3-aryl-6-(4-methoxyphenyl)-l,2,4-triazin-5-ones 112, through oxidation of the intermediate rr -adducts by air oxygen (Scheme 59) <1997JHC537>. 

Acetanisole Benzophenone-11 Bis (cyclopentadienyl) chromium Bis (cyclopentadienyl) vanadium dichloride 2,4-Bis (2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-1,3,5-triazine p-t-Butylphenyl salicylate Carbon black 2-(3,5-Di-t-butyl-2-hydroxyphenyl)-2H-benzotriazole 2-(2-Hydroxy-4-octyloxyphenyl)-2H-benzotriazole Menthyl salicylate o-Methyl benzoyl benzoate 2,2, 4,4 -Tetrahydroxy, 5,5 -di-t-butylbenzophenone Zinc oxide UV absorber, ABS... 

Stabilizers Screener carbon black, zinc oxide, talc Phenolic antioxidant ethylene-bis(oxyethylene)-bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)-propionate) 2,6,-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5,-triazine-2-ylamino) phenol 2-(1,1-dimethylethyl)-6-[[3-(1,1 -dimethylethyl)-2-hydroxy-5-methylphenyl] methyl-4-methylphenyl acrylate 2 ,3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide isotridec l-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate 3,5-bis(1,1-dimethyethyl)-4-hydroxy-benzenepropanoic acid, C13-15 alkyl esters 2,2 -isobutylidenebis(2,4-dimethylphenol) Phosphite trinonylphenol phosphite Thiosynergist 4,6-bis(octylthiomethyl)-o-cresol 4,6-bis(dodec lthiomethyl)-o-cresol 2,2 -thiodiethylene bis[3-(3,5-ditert-butyl-4-hydroxyphe-nyl)propionate] Amine nonylated diphenylamine ... 

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