1.3- Dihydroxy-4-nitrobenzene

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... 

The hydroquinone 65 is cyclized in an organic solvent at 230 to 270°C to yield 6,13-dihydroxy-quinacridone 66. Oxidation with suitable agents (such as nitrobenzene, chromic acid, nitric acid) provides the linear trans-quinacridone quinone (62) ... 

The reactions of anilines (R =4-MeO and 3-C1) and diethyl acetylmalonate in nitrobenzene at 230-235°C for 1-2 hr gave 2,4-dihydroxy-3-acetyl-quinolines (667, R = 6-MeO and 7-C1). In the case of 3-chloroaniline, a mixture of the isomeric 5- and 7-chloroquinolines was obtained (46JA324). The 7-chloroquinoline was the major isomer. 

GC-MS and HPLC analyses of electrolyzed solutions allowed the detection of aromatic intermediates such as p-benzoquinone and nitrobenzene for aniline, 4-chlorocatechol for 4-chlorophenol, 4-chlorophenol, 4-chlorocatechol, hydroquinone, and p-benzoquinone for 4-CPA, 4-chloro-o-cresol, mehylhy-droquinone, and methyl-p-benzoquinone for MCPA, 2,4-dichlorophenol, 4,6-dichlororesorcinol, chlorohydroquinone, and chloro-p-benzoquinone for 2,4-D, and 2,4,5-trichloro-phenol, 2,5-dichlorohydroquinone, 4,6-dichlororesorcinol, and 2,5-dihydroxy-p-benzoquinone for 2,4,5-T. In general, these by-products persisted in solution while the initial pollutant was degraded. 

Compounds 4 and 5 were synthesized by treatment of trimethoxy(morpholiniomethyl)silane with two mole equivalents of l,2-dihydroxy-4-nitrobenzene and 3,5-di-tbutyl-l,2-dihydroxybenzene, respeetively, in acetonitrile at room temperature (Scheme 1). 

The zwitterion 6 was obtained similarly by reaction of l-[(tri-ethoxysilyl)methyl]-l-methyl-morpholinium iodide with l,2-dihydroxy-4-nitrobenzene in boiling acetonitrile in the presence of KOH (Scheme 1). Compounds 4-6 were isolated in 75-85 % yield as crystalline solids their identity was established by elemental analyses, NMR experiments, and mass-spectrometric investigations. 

Diazo violet o-p-Dihydroxy-azo-p-nitrobenzene 10.1-12.0 yellow - violet Kolthoff... 

Monohydrate, needles from methanol, mp 268 270 [< ] -100 (0,07 g in 10 ml glacial acetic acid) (< ) -87 (0.05 g in pyridine). Practically insol in water and the usual organic solvents. Sol in nitrobenzene, phenol, aniline, pyridine, coned adds and alkalies. The water of crystn cannot be removed at KXT in vacuo Over P,0. (Merz) may be removed at 138 in high vacuum (Zempldn). Hydrolysis gives 5,7-dihydroxy -4 -methoxyflavone, D-glucose, and L-rhamnose. 

The copolymerization of 1,2,4-trioxane with the diglycidyl ether of 1,4-dihydroxy diphenyldimethylmethane (catalyzed by BF30Et2 in nitrobenzene) was studied and found to proceed via the tertiary oxonium mechanism <1996MI23>. In the range 30-60 C, a linear copolymer with high alkali and thermal stability could be obtained... 

Dihydro-5,8-dihydroxy-6,6 -dimethoxy-4 -methylnaphthaIene-2-spiro-2 -2 /7-benzofuran-l,3, 4-trione in nitrobenzene heated at 200° for 2 h->- 6,ll-dihydroxy-3,8-dimethoxy-l-methylbenzo[Z ]xanthene-7,10,12-trione. Y 74%. F.e.s. C.B. de Koning et al., J. Chem. Soc. Perkin Trans. I 1988, 3209-16. 

Preparation by Fries rearrangement of 2, 4 -diace-toxy-l,3-diphenylpropane with aluminium chloride in the presence of 2, 4 -dihydroxy-l,3-diphenylpro-pane in nitrobenzene at 50° [3579]. 

Acylation of phloroglucinol (16.2 g 1.29 x 10 mol) with p.fi-dimethyiacryi chloride occurs as reported (8). After steam distillation to remove nitrobenzene, the residue is separated by chromatography on silica gel with ether hexane 2 3 as eluent. A solid material is isolated, which upon recrystallization from chloroform yields 5,7-dihydroxy-2,2-dimethylchromanone (281). 

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