Ethyl acetate 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). 

AI3-00040, see Cyclohexanol AI3-00041, see Cyclohexanone AI3-00045, see Diacetone alcohol AI3-00046, see Isophorone AI3-00050, see 1,4-Dichlorobenzene AI3-00052, see Trichloroethylene AI3-00053, see 1,2-Dichlorobenzene AI3-00054, see Acrylonitrile AI3-00072, see Hydroquinone AI3-00075, see p-Chloro-rrr-cresol AI3-00078, see 2,4-Dichlorophenol AI3-00085, see 1-Naphthylamine AI3-00100, see Nitroethane AI3-00105, see Anthracene AI3-00109, see 2-Nitropropane AI3-00111, see Nitromethane AI3-00118, see ferf-Butylbenzene AI3-00119, see Butylbenzene AI3-00121, see sec-Butylbenzene AI3-00124, see 4-Aminobiphenyl AI3-00128, see Acenaphthene AI3-00134, see Pentachlorophenol AI3-00137, see 2-Methylphenol AI3-00140, see Benzidine AI3-00142, see 2,4,6-Trichlorophenol AI3-00150, see 4-Methylphenol AI3-00154, see 4,6-Dinitro-o-cresol AI3-00262, see Dimethyl phthalate AI3-00278, see Naphthalene AI3-00283, see Di-rj-butyl phthalate AI3-00327, see Acetonitrile AI3-00329, see Diethyl phthalate AI3-00399, see Tributyl phosphate AI3-00404, see Ethyl acetate AI3-00405, see 1-Butanol AI3-00406, see Butyl acetate AI3-00407, see Ethyl formate AI3-00408, see Methyl formate AI3-00409, see Methanol AI3-00520, see Tri-ocresyl phosphate AI3-00576, see Isoamyl acetate AI3-00633, see Hexachloroethane AI3-00635, see 4-Nitrobiphenyl AI3-00698, see IV-Nitrosodiphenylamine AI3-00710, see p-Phenylenediamine AI3-00749, see Phenyl ether AI3-00790, see Phenanthrene AI3-00808, see Benzene AI3-00867, see Chrysene AI3-00987, see Thiram AI3-01021, see 4-Chlorophenyl phenyl ether AI3-01055, see 1.4-Dioxane AI3-01171, see Furfuryl alcohol AI3-01229, see 4-Methyl-2-pentanone AI3-01230, see 2-Heptanone AI3-01231, see Morpholine AI3-01236, see 2-Ethoxyethanol AI3-01238, see Acetone AI3-01239, see Nitrobenzene AI3-01240, see I idine AI3-01256, see Decahydronaphthalene AI3-01288, see ferf-Butyl alcohol AI3-01445, see Bis(2-chloroethoxy)methane AI3-01501, see 2,4-Toluene diisocyanate AI3-01506, see p,p -DDT AI3-01535, see 2,4-Dinitrophenol AI3-01537, see 2-Chloronaphthalene... 

Reactions of various l-(l,2-propadienyl)cyclopropanols having a substituent at the 1- or 3-position of the propadienyl moiety 55 proceed smoothly at between 0°C and room temperature with 1.1 mole amounts of Co2(CO)8 in either THF or ethyl acetate, and various 2-monosubstituted or 2,3-disubstituted 1,4-hydro-quinone derivatives 58 are obtained in good yields (Scheme 25). In particular, 1-(1,2-propadienyI)cycIopropanoI having the ferf-butyldimethylsilyl group at the 1-position of the 1,2-prop adienyl moiety gives a high yield of the silylated hydroquinone. 

Dehydrogenation of 4,4 -dimethoxydibenzyl [1, 219, before references]. Findlay and Turner24 added 103 mg. of DDQ dissolved in 1.5 ml. of dioxane to a solution of 100 mg. of 4,4 -dimethoxydibenzyl and refluxed the mixture in an oil bath at 105° for 18 hrs. The initially deep green solution became pale yellow as the hydroquinone crystallized. After cooling, the solid was removed by filtration and washed with warm benzene (1 ml.) and warm chloroform (6 ml.) and dried to give 95 mg. of pure (4). A solution of the semisolid residue in 5 ml. of ethyl acetate was passed through a column of 2 g. of neutral alumina and the column was eluted with 100 ml. of ethyl... 

Monomer, flake-like crystals from benzene, d ,1 1-122, mp 84.5 . bp2 87° hps 103° bp2) 125°. Solubilities In g/ (00 ml solvent at 30° water 215.5 methanol 155 ethanol 86.2 acetone 63,1 ethyl acetate 12.6 chloroform 2.66 benzene 0.346 heptane 0.0068. The solid may be stored in a cool, dark place. Readily polymerizes at the mp or under uv light. Commercial sol ns of the monomer may be stabilized with hydroquinone, terr-butylpyrocatechol, N-phenyl-2-naph thylamine or other antioxidants. LD, i.p. in mice 170... 

White granules. Soly is dependent upon the degree of Substitution. Commercial ethyl cellulose has an ethoxy content of 43-50%. A 47% product softens at ]40° and is sol in ethyl acetate, ethylene dichloride, benzene, toluene, xylene, butyl acetate, acetone, methanol, ethanol, hutanol, carbon tetrachloride. To avoid brittleness, ethy] cellulose formulations usually include an antioxidant such as hydroquinone monobenzyl ether, 4-hexylpyrOcatechol, Or diphenylamine. 

Those methods of purifying vinyl acetate which involve washing of the monomer usually seem to be concerned with the removal of hydroquinone, acetic acid, and acetaldehyde. The use of aqueous solutions for these procedures actually is somewhat questionable in view of the ease of hydrolysis of vinyl acetate (comparable in rate to the hydrolysis of ethyl acetate). In aqueous alkali, the hydrolysis rate of this monomer is said to be 370 times as fast as in water [2]. Nevertheless, such procedures have been suggested and are given here for information only as a typical example of this method. 

A mixture of cyanomethyl acrylate, piperazine hexahydrate, a little hydroquinone, and ethyl acetate heated 3 hrs. at 70° l,4-bis(cyanomethyl)piperazine. Y 82.7%. F. e. s. R. Harada and Y. Kinoshita, Bull. Chem. Soc. Japan 40, 2706 (1967). 

A mixture of acridizinium tetrafluoroborate and a twofold excess of freshly distilled indene was refluxed for 6 h in acetonitrile with a small quantity of hydroquinone. The adduct was isolated by evaporation of the solvent under reduced pressure and trituration of the residue with ethyl acetate or anhydrous ethyl ether to remove any polymer that might have been formed. After the trituration, a 96% yield of adduct was obtained. 

Definition Monomethyl ether of hydroquinone Empiricai C7H8O2 Formuia CH3OC6H4OH Properties Colorless to wh. waxy solid or cryst. powd. caramel/phenol odor sol. in water, benzene, ether, acetone, ethyl acetate, alcohol, oxygenated soivs. m.w. 124.14 dens. 1.55 (20/20 C) vapor pressure < 0.01 mm Hg (20 C) m.p. 

Figure 5.9 Thin-layer chromatograms of mixtures of antioxidants. Mobile phase benzene - ethyl acetate - acetone (100 5 2). Columns are (a) phenols, (b) amines, (c) hydroquinones, (d) miscellaneous antioxidants, and (e) mixtures of unknown extract formulations Reproduced from Simpson and Currell, RSC [32]...

Methyl-1,3-cyclohexanedione (126.1 g, 1.0 mol) and 300 mL distilled water are placed into a 1 liter round-bottomed flask fitted with a reflux condenser and a thermometer. Acetic acid (3.0 mL), hydroquinone (1.1 g) and methyl vinyl ketone (142 g, 167 mL, 2 mol, freshly distilled) are added and the resulting mixture is heated for 1 h at 75 °C. After cooling to room temperature, the reaction mixture is saturated with 103 g of sodium chloride and poured into 400 mL of ethyl acetate. After separation of the layers, the aqueous phase is twice extracted with ethyl acetate (150 mL each). The combined organic extracts are washed with two 200 mL portions of brine solution, dried over sodium sulfate, filtered, and then concentrated in vacuo to yield 210.8 g of 2-methyl-2-(3-oxobutyl)-1,3-cyclohexanedione as a pale yellow oil. 

Liquid-phase reductive extraction with zinc chloride in an acid medium was tested to extract K vitamers as acetonitrile soluble hydroquinones from dairy products [125,126]. Acid hydrolysis [125] proved advantageous in isolating long chain menaquinones from cheese, provided the digestion time (10 min) was short. Semipreparative LC [125,127,128] and SPE [126] have sometimes been employed as a cleanup and concentration step after solvent extraction. Matrix solid-phase dispersion (MSPD) followed by PLE wifh ethyl acetate at 50°C and 1500 psi [129] and SEE using carbon dioxide at 8000 psi and 60°C [130] are fast, alternative procedures for exfracfing phylloquinone. 

The solvent used in these dimerization reactions dictates the activity of the catalyst. Besides benzene and dioxane, acetic acid [246,247], halogenated hydrocarbons [245,247], nitroderivatives [247], sulfones, tetrahydrofuran (THF), ethyl acetate, phenol, dimethylformamide, hydroquinone, catechol, benzyl alcohol, salicylic acid, anisole, and acetone have been used [247]. In solvents like benzene and chlorohydrocarbons and in highly polar solvents like dimethylsulfoxide and dimethylformamide, dimerization does not occur. The reaction proceeds in solvents containing oxygen atoms. The dissociative solvents like phenol and acetic acid show high solvent effect. In carboxylic acids the rate of dimerization decreases with an increase in pK . 

The conversion of ethyl alcohol by way of acetaldehyde into acetic acid is the chemical expression equivalent to acetic fermentation. In this process the acetic bacteria utilise atmospheric oxygen in order to bind the hydrogen. That the hydrogen which has to be removed is activated, and not the oxygen (as was formerly thought), is shown by experiments in which oxygen is eaxluded and replaced by quinone the bacteria produce acetic acid from alcohol as before and the quinone is reduced to hydroquinone. 

Reagents required for the conventional method include sodium hydrogen sulfite (Sigma-Aldrich, cat. no. 243973), hydroquinone (Sigma), NaOH (3M), mineral oil. Wizard DNA Cleanup system (Promega), isopropanol, ammonium acetate (lOAf), glycogen, and ethyl alcohol. 

Figure 2. Rejection performance of five different RO membranes (6). A, methanol B, aniline C, formaldehyde D, methyl acetate E, acetic acid F, urea G, ethanol H, acetone 1, hydroquinone J, isopropyl alcohol Kt glycerol L, sodium chloride M, ethyl ether N, phenol. Conditions pressure, 40.8 atm temperature, 24 °C feed, 0.30 gal/min.

Copper(II) and cerium(IV) have been studied as oxidants in acetonitrile. The copper(II)-copper(I) couple has an estimated electrode potential of 0.68 V relative to the silver reference electrode. It has been studied as an oxidant for substances such as iodide, hydroquinone, thiourea, potassium ethyl xanthate, diphenylbenzidine, and ferrocene. Cerium(IV) reactions are catalyzed by acetate ion. Copper(I) is a suitable reductant for chromium(VI), vanadium(V), cerium(IV), and manganese(VII) in the presence of iron(III). For details on many studies of redox reactions in nonaqueous solvents, the reader is referred to the summary by Kratochvil. ... 

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