4- Nitro-1,2-dihydroxybenzene

PVC, polyamides, unsaturated crosslinked polyesters, ABS, and wood . Di- and tri-benzotriazole photostabilizers, such as (874) and (875) are synthesized from 2-nitro-benzenediazonium salts and an excess of 1,3-dihydroxybenzene or 1,3,5-trihydroxybenzene <85Mi 40i-0l>. The dibenzotriazole derivatives (874b and 875b) can be used as polymerizable acrylic UV absorbers <84PB237>. A few or/Ao-urethane and -trimethylsilane substituted 2-phenylbenzotriazoles (876 and 877) show similar photostabilization activity . Weather resistance of low-density polyethylene is improved by the addition of a benzotriazole-type photostabilizer <90M140i-04>. 

Hirose, M., Yamaguchi, S., Fukushima, S., Hasegawa, R., Takahashi, S. Ito, N. (1989) Promotion by dihydroxybenzene derivative of V-methyl-V -nitro-A-nitrosoguanidine-induced F344 rat forestomach and glandular stomach carcinogenesis. Cancer Res., 49, 5143-5147... 

Resorcin, Nitro (Ger). See under Mononitro-dihydroxybenzene in Vol 5, D1271-L... 

The transformation of chlorophenols upon irradiation of nitrate mainly yields hydroxylated derivatives, while no nitration was observed. The absence of nitro derivatives can be attributed to the electron-withdrawing character of the chlorine atoms, inhibiting nitration. Dihydroxybenzenes and benzoquinone were also observed implying that a dechlorination process, induced by either hydroxyl or light, takes place in the system [123]. 

The naphthylamines may be prepared by reduction of the corresponding nitro compound, but they are readily accessible from naphthois by the Bucherer reaction The naphthol is heated, preferably under pressure in an autoclave, with ammonia and aqueous sodium hydrogen sulfite solution, when an addition-elimination sequence occurs. The detailed mechanism is not completely elucidated, but the Bucherer reaction is restricted to those phenols that show a tendency to tautomerize to the keto form, such as the naphthois and 1,3-dihydroxybenzene (resorcinol). Using 1-naphthol for illustration, the first step is addition of the hydrosulfite across the 3,4-double bond of either the enol or keto tautomer (Scheme 12.9). Nucleophilic attack by ammonia at the carbonyl group... 

All types of alcohols and phenols are acylated by anhydrides. The reaction is catalyzed by a small amount of sulfuric acid, zinc chloride, acetyl chloride, sodium acetate, or pyridine. r-Butyl alcohol gives /-butyl acetate in 60% yield. Acetylation of phenols may be accomplished in an aqueous alkaline solution, the acylation proceeding more rapidly than the hydrolysis of the anhydride. The yields are above SX)%. Phenol, dihydroxybenzenes, naphthols, and phenols carrying nitro, amino, halo, carboxyl, or carbomethoxyl groups are acetylated by this procedure. ... 

Nitro l,3-dihydroxybenzene, lemon yel ndls + 5 20 (from water), anhyd crysts (from chlf or CCI4), mp 120-22°(Ref 4)... 

Other Names Pyrocatechol, 4-nitro- 1,2-Dihydroxy -nitrobenzene 3,4-Dihydroxy-1-nitrobenzene 3,4-Dihydroxynitrobenzene 4-Nitro-l,2-benzenediol 4-Nitro-l,2-dihydroxybenzene 4-Nitrobenzcatechin 4-Nitrocatechol 4-Nitropyrocatechol NSC 80651 p-Nitrocatechol CA Index Name 1,2-Benzenediol, 4-nitro-CAS Registry Number 3316-09-4 Merck Index Number Not listed Chemical Structure... 

Examples of cocrystals containing chains, ribbons, and other infinite ID motifs (Scheme 8) include bipyridine dihydroxybenzene, melamine cyanuric acid, bipyridine (fluorinated)dibromobenzene, 2-aminopyridine dicar-boxylic acids, triaminopyrimidine barbituric acid, 2-aminopyrimidine dicarboxylic acid, " 1,2,3-trihydroxy-benzeneihexamethylenetetramine, diols diamines, bis-benzimidazole dicarboxylic acids, and 2-amino-5-nitro-pyrimidine 2-amino-3-nitropyridine." ... 

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