Petroleum hydroquinone

The reaction mixture was removed from the vessel and distilled at a pressure of 30-60 mm, and a bath temperature of 30°C to 50°C until the methanol had all been removed. The extremely viscous tarry residue remaining in the still pot was given a very crude distillation, the distillate boiling at B2°C to 1 32°C/2 mm. In an attempt to purify this distillate by a more careful distillation, 5.3 g of a liquid distilling from 53°C to 150°C/5 mm was collected. At this point, much solid sublimate was noted not only in this distillate but in the condenser of the still. 7 g of the solid sublimate was scraped out of the condenser of the still. Recrystallization of the sublimate from ethyl acetate containing a small amount of petroleum ether gave beautiful crystals melting at 175°C to 177°C (5 g). Infrared analysis confirmed that this compound was hydroquinone (9% conversion). 

Hydroprocessing, in petroleum refining, 18 654-657 Hydropulping, 10 535 Hydropyrolysis, coal liquefaction, 6 854 Hydroquinolines, 21 198-199 Hydroquinone (HQ) from benzene, 3 620 as a black-and-white chemical reducing agent, 19 205-206 in bleaching preparations, 7 847 clathrates, 14 160 dye releaser, 19 291-292 inclusion compounds in, 14 172, 174 intermediate used in oxidation hair dyes, 7 858t... 

A solution of the sulfolene (6) (6.5 g, 15.9 mmol), pyridine (15 ml) and a catalytic amount of hydroquinone in xylene (350 ml) was refluxed for 6h. After being cooled the volatiles were removed and the residue filtered through a short pad of deactivated (5% Et3N) silica gel using petroleum ether to yield the diene (7) (2.5 g, 47%), b.p. 97-95°C/0.2 torr. 

Suspend 0.5 g of the quinone in 2.5 ml of pure acetic anhydride, and add 0.5 g of zinc powder and 0.1 g of powdered, anhydrous sodium acetate. Warm the mixture gently until the colour of the quinone has largely disappeared and then boil for 1 minute. Add 2 ml of glacial acetic acid and boil again to dissolve the product and part of the precipitated zinc acetate. Decant the hot solution from the zinc acetate and zinc, and wash the residue with 3-4 ml of hot glacial acetic acid. Combine the solutions, heat to boiling, carefully add sufficient water to hydrolyse the acetic anhydride and to produce a turbidity. Cool the mixture in ice, filter off the diacetate of the hydroquinone and recrystallise it from dilute ethanol or from light petroleum. 

Phenolic wastes are one of the most prevalent forms of chemical pollutants in industry today. The major sources of phenolic waste are insulation fiberglass manufacturing, petroleum refineries, textile mills, steel making, plywood, hardboard production, manufacture of organic chemicals, paint stripping, and wood preservatives. Eisenhauer (1964) first studied oxidation of phenolic wastes with Fenton s reagent. It has been demonstrated that the oxidation of phenol involves the intermediate formation of catechol and hydroquinone (Merz and Waters, 1949 Stein and Weiss, 1951 Wieland and... 

Aniline is a compound used in the synthesis of insecticides, chemical brighteners, and dyes and is a by-product of the petroleum, paper, and coal industries. The photocatalytic oxidation of aniline was studied by Sanchez et al. (1997). The reaction was found to follow Langmuir-Hinshelwood kinetics. The adsorption rate constant and the reaction rate constants were also reported. Higher yields were reported for acidic conditions and values near the pH at the point of zero charge (pHpZC) of Ti02. The rate of photocatalytic oxidation was also found to increase with the addition of small amounts of Fe. Hydroquinone is the main intermediate formed from the reaction. Photocatalytic reactions were carried out in a 130-cm3 cylindrical Pyrex cell. Medium-pressure mercury lamps provided UV light. Initial concentrations of 1.0 x 104 and 2 g/L were prepared. The pH of the solutions was adjusted and reactions were carried out for 15 min. Concentrations of aniline and byproducts formed were determined by HPLC. 

Kalf, G. Jefferson Medical College Philadelphia, PA Influence of hydroquinone on benzene leukemogenesis American Petroleum Institute... 

Escherichia coli (see Draths and Frost, 1994). Hydroquinone is a very practical intermediate in the manufacture of polymeric materials—almost 2 billion kg of adipic acid are produced from it and used annually in the manufacture of nylon 66. Most commercial syntheses of adipic acid utilize benzene as the starting material, derived from the benzene/toluene/xylene (BTX) fraction of petroleum refining. Benzene is hydrogenated over a metal catalyst to form cyclohexane, which is then oxidized over another catalyst that produces both cyclohexanone and cyclohexanol. See Figure 12.6. These molecules are catalytically oxidized in the presence of nitric acid to form adipic acid. 

Quinone is formed as yellow crystals and has a characteristic irritating odor like that of chlorine. It is slightly soluble in water, alcohol, ether, hot petroleum ether, and alkalis. Quinone is an oxidizing agent and is reduced to hydroquinone. It has been declared a federal hazardous air pollutant and was identified as a toxic air contaminant in April 1993 under AB 2728. 

Extraction of cryptophenois and enok. Phenols insoluble in aqueous alkali, for example 2,4,6-triallylphenol, can be extracted from petroleum ether with Claisen s alkali. Vitamin K, is easily isolated from a 3-5% alfalfa concentrate by shaking an alcoholic suspension of the oil with aqueous sodium hydrosulfite, extracting with petroleum ether, and extracting the Kj hydroquinone from petroleum ether with Claisen s alkali. The yellow extract is diluted with water and Ki hydroquinone OH CHj CH, CHj CH,... 

The work of Frost et al. has focused on the aromatic pathway with respect to the biosynthesis of quinoid organics such as benzoquinone and hydroquinone, as well as adipic acid production [194-197]. The same principles have been used whereby a cloned gene is overexpressed, which allows the recombinant organism to funnel carbon down a specific, selected metabolic pathway. Although currently tlrese compounds are synthesized from petroleum-based feed stocks primarily for economic reasons, environmental concerns and the shortage of these starting... 

When Ar = />-CH3OC6H4 yields of a,G)-diiodides are very good up to = 40. If the cleavage is carried out by boiling in open vessels, the solid material is filtered off after some hours and heated again with fresh hydriodic acid. The crude diiodides are washed with water, dried, and freed from humin-like decomposition products of hydroquinone by extraction in a Soxhlet with light petroleum. 

Methyl-4,5-heptadien-2-one 9 2-Methyl-3-butyn-2-ol (172 g), light petroleum (b.p. 60 to 90° 800 ml), hydroquinone (0.4 g), and isopropenyl methyl ether (432 g) are treated with p-toluenesulfonic acid (0.2 g). There is an exothermic reaction, after which the mixture is... 

Collective name for polyprenylated 2,3-dimethylben-zoquinone derivatives, [e.g., PQ-9 (n=9), C5jH ,02, Mr 749.22, bright yellow platelets, mp. 48-49 C, u max 314 nm (petroleum ether)], isolated from chloro-plasts. The P. play a role as redox substrates in photosynthesis for cyclic and non-cyclic electron transport where they are converted reversibly into the corresponding hydroquinones (plastoquinols). The biosynthesis of P. proceeds from homogentisic acid, a product of L-tyrosine degradation, through prenylation and methylation (methyl group from L-methionine) to the plastoquinols which are dehydrated to the P.. ... 

Since pyrethrins are highly photolytic, antioxidants are often added to preparations to stabilize formulations antioxidants adjoin include pyrocatechol, pyrogal-lol, hydroquinone, and l-benzene-azo-2-naphthol. Practically, all pyrethrins and many pyrethroids are commonly combined to additives (including synergists), some formulations include additional insecticides, insect repellents, or both, and many contain hydrocarbon solvents [3] to enhance their insecticidal activity. Pyrethrin and pyrethroid sprays may also be water based or be alcohol or petroleum based, which increases the overall toxicity. It is known that concomitant use of pyrethrins and pyrethroids with synergists such as piperonyl butoxide, A -octyl bicycloheptene dicarboximide, sulfoxide, sesamin, sesame oil, sesamolin, isosafrole, and organophosphorus compounds or carbamates may increase toxicity by mechanisms involving inhibition of microsomal oxidation [4]. 

Clathrate compounds are also formed with organic non-aqueous host species, e.g. hydroquinone, phenol, monoami-nenickel cyanide, methylnaphthalene, etc. (Findlay, 1962). Clathrate compounds formed with monoaminenickel cyanide as host and henzene/thiophene as guest (Figure 4.1.23 (b)) are of interest in petroleum refining the selectivity of the host for benzene is much higher. 

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