Pyrocatechol from benzene

Kennedy and Stock reported the first use of Oxone for many common oxidation reactions such as formation of benzoic acid from toluene and of benzaldehyde, of ben-zophenone from diphenyhnethane, of frawi-cyclohexanediol Ifom cyclohexene, of acetone from 2-propanol, of hydroquinone from phenol, of e-caprolactone from cyclohexanone, of pyrocatechol from salicylaldehyde, of p-dinitrosobenzene from p-phenylenediamine, of phenylacetic acid from 2-phenethylamine, of dodecylsulfonic acid from dodecyl mercaptan, of diphenyl sulfone from diphenyl sulfide, of triphenylphosphine oxide from triphenylphosphine, of iodoxy benzene from iodobenzene, of benzyl chloride from toluene using NaCl and Oxone and bromination of 2-octene using KBr and Oxone . Thus, they... 

Diazo coupling involves the N exocyclic atom of the diazonium salt, which acts as an electrophilic center. The diazonium salts of thiazoles couple with a-naphthol (605). 2-nitroresorcinol (606), pyrocatechol (607-609), 2.6-dihydroxy 4-methyl-5-cyanopyridine (610). and other heteroaromatic compounds (404. 611) (Scheme 188). The rates of coupling between 2-diazothicizolium salts and 2-naphthol-3.6-disulfonic acid were measured spectrophotometrically and found to be slower than that of 2-diazopyridinium salts but faster than that of benzene diazonium salts (561 i. The bis-diazonium salt of bis(2-amino-4-methylthiazole) couples with /3-naphthol to give 333 (Scheme 189) (612). The products obtained from the diazo coupling are usuallv highly colored (234. 338. 339. 613-616). 

There are two dihydroxy benzenes that can result from reaction (3.131)— hydroquinone and pyrocatechol. It has been suggested that they react with oxygen in the following manner [55] ... 

The reaction mixture from acidified dihydroxyacetone also included a series of seven di- and tri-hydroxybenzenes (see Scheme 4), namely, 2,3-dihydroxytoluene (16), pyrocatechol (17), 3,4-dihydroxy toluene (19), 3,5-dimethyl-l,2-benzenediol (20), 1,2,3-trihydroxybenzene (pyrogallol) (21), 1,2,4-trihydroxy benzene (22), 3,4,5,6-tetrahydroxy-2-methy 1-acetophe-none, and 2,3-dihydroxy-5,6-dimethyl-p-benzoquinone. Many of these same phenolic compounds are present after hexoses are similarly treated... 

Of special interest for petrochemical and organic synthesis is the implementation of thermodynamically hindered reactions, among which incomplete benzene hydrogenation or incomplete cyclohexene and cyclohexadiene dehydrogenation should be mentioned. Cost-effective methods of cyclohexene production would stimulate the creation of new processes of phenol, cyclohexanol, cyclohexene oxide, pyrocatechol synthesis, cyclohexadiene application in synthetic rubber production, and a possibility for designing caprolactam synthesis from cyclohexene and cyclohexadiene via combined epoxidation. At present, the most... 

Pyrocatechol (25 g, 0.23 mol) and benzene-1,2-diamine (24 g, 0.22 mol) were heated in a scaled tube at 200-210 X for 35 40 h. The product was digested rapidly portion-wise with H O at 60 X (400 mL in total), giving a green residue of crude 5,10-dlhydrophenazinc which was dried in vacuo (NaOH) and then placed in a 250-mL wide-armed retort fitted with an Oj lead, and contained in an air-oven so that Va of the arm of the retort projected out of the oven. A slow stream of dry was then passed through the retort and the temperature was raised to 210 220 C. Almost pure phenazine sublimed into the side-arm during 5-7 h and was recrystallized from EtOH yield 51 % mp 171 -172 C. 

Dehydrogenation of pyrocatechol by silver oxide gives 0-benzoquinone.469 For preparation of amino-0-benzoquinones see Homer and Lang.470 Hydro-quinones are also dehydrogenated with success by lead tetraacetate.222 Further, 2,3-dichloro-5,6-dicyano-l,2-benzoquinone is obtained from the hydroquinone in 83% yield when a solution of the latter in 5% ethanolic hydrogen chloride is shaken with a mixture of Pb02 and benzene.471... 

Interfacial polymerization was employed to produce aromatic polyesters from 2,5-furan dicarbonyl dichloride with various bis-phenols such as resorcinol, pyrocatechol, hydroquinone, and 2,2-bis(4-hydroxy-phenyl) propane. When 2,5-furan dicarbonyl dichloride was combined with 2,2-bis(4-hydroxyphenyl)propane, workers were able to obtain a maximum yield and maximum logarithmic viscosity number of 80% and 0.17, respectively, when the polymerization solvent was benzene at 25 with two equivalents of sodium hydroxide. In a more in-depth study, this same polyester 14... 

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