Solids decoloration

Methyl mercaptan (1.92 g, 0.040 mol) was added to a cooled solution of r-BuOK (10 g, 0.090 mol) in dry DMSO (50 mL). The mixture was stirred for 30 min followed by the dropwise addition of a solution of l,l-dichloro-la,9b-dihydrocyclopropa[/]phenanthrene (2.61 g, 0.010 mol) in dry DMSO (50 mL). The mixture was stirred at rt for 3 h and then poured into HjO. The resulting solution was extracted with CHCI3, washed with H O, and dried (Na2S04). After removal of solvent, the product was isolated as a yellow solid. Decoloration with charcoal and recrystallization from pentane gave2.36 g (83%) of colorless material mp 149-149.5°C. 

The toluene solution from the previous step was treated with an ethanol solution of NaOEt (0.1 mol in 100 ml) at O C. When about a quarter of the solution had been added a thick precipitate formed and ether (100 ml) was added to maintain a fluid slurry. The remainder of the NaOEt was added and the slurry was stirred overnight. The solid was collected and w ashed with ether. It was then mixed with ether (200 ml) and 2NHC1 (75 ml) and shaken in a separatory funnel until the solid dissolved. The ether layer was washed with 2NHHC1 (2 X 50ml) and water and dried over MgS04. The solution was decolorized with Magnesol and evaporated to give the a-nitro ester as a red oil. 

The autoclave is cooled to room temperature, and the carbon dioxide is bled off. The solid reaction product is taken from the autoclave, pulverized, and dissolved in 1 1. of water at 50-60°. Ten grams of decolorizing carbon is added, and the mixture is stirred well and filtered to remove cadmium salts and carbon. The filtrate is heated to 80-90° and acidified with concentrated hydrochloric acid to pH 1 (Note 5). 2,6-Naphthalenedicar-boxylic acid precipitates. It is separated from the hot mixture by filtration. It is then suspended in 500 ml. of water at 90-95° (Note 5), separated by filtration, and washed successively with 300 ml. of water, 300 ml. of 50% ethanol, and 300 ml. of 90% ethanol. After being dried at 100-150°/150 mm. in a vacuum oven, the 2,6-naphthalenedicarboxylic acid weighs 42-45 g. (57-61%). It decomposes on a heated block at 310-313°. 

Charcoal is not only employed in activated form for decoloring and adsorbing dissolved admixtures but also in its unactivated form as a filter aid. It can be used in suspensions consisting of aggressive liquids (e.g., strong acids and alkalies). As with sawdust, it can be used to separate solids that may be roasted. On combustion, the charcoal leaves a residue of roughly 2 percent ash. Particles of charcoal are porous and form cakes of high density but that have a lesser retention ability than does diatomite. 

Propenyl)aniline (1, 1.0 g, 7.52 mmol), PdCl2(CH3CN)2 (0.195 g, 0.75 mmol), benzoquinone (0.812 g, 7.52 mmol), and LiCl (3.158 g, 75.2 mmol) were combined in THF (95 mL). After 5 h at reflux, the solvent was removed and the residue was stirred with ether and decolorizing charcoal for approximately 20 min and filtered. The filtrate was washed five times with 50-mL portions of 1 M NaOH. The solvent was removed by vacuum, and the residue was placed on a silica gel column and eluted with 3 1 petroleum ether/ether. 2-Methylindole (2, 0.818 g, 86%) was collected as a white, crystalline solid, identical with authentic material. ... 

The crude product separates as a solid from the reaction medium and is recovered by filtration, and it is then washed thoroughly with ether and dissolved in 350 ml 1 N HCI. Then, approximately 250 ml of the aqueous solvent is removed with a rotary evaporator and the evaporation residue combined with 125 ml methanol and filtered through decolorizing charcoal. The product is precipitated as the HCI salt by the addition of 7 parts of acetone. The resulting crystalline material is removed by filtration dried at 40°C with vacuum, and has a melting point of about 242°C and Is used without further purification. 

Drying over anhydrous sodium sulfate containing decolorizing carbon followed by removal of the solvent by distillation at reduced pressure affords an oil which solidifies on standing. Recrystallization of that solid by dropwise dilution with water of a methanol solution affords 17o -ethvnvl-19-norandrost-4-ene-3(3,17(3-diol 3,17-diacetate, melting at about 126° to 127°C. 

A mixture of 4,4 parts of 1-chloro-3-(1-naphthoxy)-2-propano and 16 parts of isopropylamine is heated in a sealed vessel at 70° B0°C for 10 hours. The vessel is cooled and to the contents there are added 50 parts of water. The mixture is acidified with 2N hydrochloric acid, and washed with 50 parts of ether. The aqueous phase Is decolorized with carbon, and then added to 50 parts of 2N sodium hydroxide solution at 0°C, The mixture is filtered. The solid residue is washed with water, dried, and crystallized from cyclohexane. There is thus obtained 1-isopropylamino-3-(1-naphthoxy)-2-propanol, MP 96°C. 

A 15.7 g (0.1 mol) of 2,6-dihydroxy methylpy rid in e hydrochloride are suspended in 176 ml of acetonitrile, and 20fi ml (0.15 mol) of triethylamine are added to the suspension. Thereafter 13 ml (0.22 mol) of methyl isocyanate are added dropwise to the reaction mixture at 20°C to 25°C. The reaction mixture is stirred at 20°C to 30°C for one hour, thereafter boiled for 3 hours, and finally the solvent is evaporated under reduced pressure. 35 to 40 g of a greyish, crystalline residue are obtained, which Is a mixture of 2,6-dihydroxymethylpyridine-bis-(N-methylcarbamate) and triethylamine hydrochloride. The obtained residue is dissolved in 80 ml of hot water, decolorized with 2 g of activated carbon when hot, and filtered after 30 minutes of stirring. The filtrate is cooled, the resulting crystal suspension is stirred at 0°C to 5°C for 3 hours, the solids are filtered off, and dried at 50°C to 60°C. 

Preparation of 3 5-diiodo-4-(4 -hydroxyphenoxy)phenylacetic acid (diac) A solution of ethyl 3 5-diiodo-4-(4 -methoxyphenoxy)phenyl acetate (9.5 g) in acetic acid (60 ml) was heated under reflux with hydriodic acid (SG 1.7, 50 ml) and red phosphorus (0.5 g) for 1 hour. The hot solution was filtered and the filtrate concentrated at 50°C and 15 mm of mercury to above 20 ml. The residue was treated with water (70 ml) containing a little sodium thiosulfate to decolorize the product. The solid was collected by filtration and purified by the method of Harington and Pitt-Rivers [Biochem. J. (1952), Vol. 50, page 438]. Yield 8,36 g (95%). After crystallization from 70% (v/v) acetic acid it melted at 219°C. 

The resulting white solid is collected on a filter, air dried, redissolved in 2,500 parts water at 95°C and the resulting solution treated with decolorizing charcoal and clarified by filtration. The cooled filtrate is made alkaline with ammonia and the product, crude 3-(1-piperidyl)-Tcyclohexyl-1-phenyl-1-propanol is collected. The hydrochloride melts with decomposition in ten seconds in a bath held at 258.5°C. The alcohol melts at 114.3° to 115.0°C, according to U.S. Patent 2,716,121. 

Diethyl malonate or a derivative (0.25 mol) and benzene-1,2-diamine (27 g, 0.25 mol) were added to a solution of NaOEt prepared from sodium (11.5 g. 0.5 g-atom) and EtOH (300 mL). The EtOH was distilled off, finally under reduced pressure, and the residue was heated at 180-200 C under N2 for 4 h and then stirred with ice. The mixture was acidified with coned HC1 and the resulting solid was collected, washed with H20 and recrystallized (EtOH) with the addition of decolorizing charcoal if necessary. 

Best Preparation on a Laboratory and Commercial Scale. A. Methylene diform amide. In a 2fi round bottom 1 neck flask are placed 540g of formamide and 70g of hexamine. The flask is fitted with a wide bore air condenser topped with a w jacketed reflux condenser, and the flask held at 140 for 5 hours. It is chilled in ice, the solid filtered, and washed on the filter with 90g of formamide. The cmde prod may be used in the next step. For a pure sample,- the crude solid is dissolved in et ale, decolorized with charcoal, and the soln chilled, mp 142—43°... 

It is obtained by distn of high-boiling petroleum fractions, followed by purification. The latter operation consists of treatment with coned sulfuric acid, then coned Na hydroxide soln, and filtration thru decolorizing carbon. In order to reduce the solid paraffins, the oil is chilled aind filtered... 

When a test confirms the presence of a substance without determining the amount of substance present, the process is called qualitative analysis. In this activity, you will detect the presence of potassium in coffee by the characteristic yellow color that appears when potassium ions react with sodium hexanitrocobaltate. To make it easier to detect the yellow color, the coffee solution will be decolorized with charcoal, an allotropic form of solid carbon. 

Through the separatory funnel are introduced 1600 cc. of water, 500 cc. of c. p. acetone, and 372 cc. of glacial acetic acid. The stirrer is started and the temperature of the water bath is raised to 70-80°, so that the mixture in (he flask is at about 65° (Note 2). Then 354 cc. (7.3 moles) of bromine is carefully added through the separatory funnel. The addition is so regulated as to prevent the accumulation of unreacted bromine (Note 3). The addition requires one to t wo hours. As a rule the solution is decolorized in about twenty minutes after the bromine has been added. When the solution is decolorized, it is diluted with 800 cc. of cold water, cooled to io°, made neutral to Congo Red with about 1000 g. of solid anhydrous sodium carbonate, and the oil which separates is collected in a separatory funnel and dried with 80 g. of anhydrous calcium chloride. After drying, the oil is fractionated and the fraction boiling at 38 48°/13 mm. is collected. The yield is 470 480 g. (47—48 per cent of the theoretical amount). It may be used without further purification for the preparation of acetol (p. 1), but if a purer product is desired, the above product is refractionated... 

Upon adding the calculated amount of water to ethyl oxomalonate, decolorization takes place immediately with evolution of heat, and on cooling a solid mass of ethyl dihydroxy-malonate results. After recrystallization from chloroform the product melts at 56-57°. (Communicated by Elizabeth Gilman and T. B. Johnson.)... 

Boer CG, Obici L, de Souza CGM, Peralta RM (2004) Decolorization of synthetic dyes by solid state cultures of Lentinula (Lentinus) edodes producing manganese peroxidase as the main ligninolytic enzyme. Bioresour Technol 94 107-112... 

Nam IH, Kim YM, Chang YS (2007) Decolorization of reactive dyes by a thermostable laccase produced by Ganoderma lucidum in solid state culture. Enzyme Microb Technol 40 1662-1672... 

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