Charcoal brown

M. von Duttenhofer (1843-1903) nitrated brown charcoal (used for prepn of C/82) by Schultze s method to obtain colloided rifle powder RCP (Rottweiler Cellulose Pulver) which was adopted by the German Army in 1884, but its compn was kept secret until 1887 (See also Vol 5 of Encycl, p D1581, under Duttenhofer s Smokeless Propellant ) (Ref 44, p 244)... 

Brown Charcoal. A product made by slightly carbonizing rye straw and used in the manuf of... 

Charcoal, Brown, See Brown Charcoal and also Davis(1943), 42... 

Adsorption by carbon, which is one of the oldest adsorption methods used, has been reviewed and evaluated for the preconcentration of trace metals (794). Many authors have discussed the preparation of activated charcoal and carbon from a wide variety of usually local sources. The applications to water treatment are far too numerous to mention other than a few. Jo (795) carbonized a resin and a gum and hydrated the residue above 600 C to produce an adsorbant selective for cadmium(II). Kuzin et al, 196) used deashed active carbon and oxidized carbon for the quantitative sorption of copper, lead, zinc, and nickel from nearly neutral solutions containing 1-2 M alkali-metal halide. Pearson and Siviour (797) converted the metal-ion species to amine complexes before adsorbing these onto carbonaceous materials such as brown charcoal char or cellulose. Mercury vapor can be removed from a solution by reduction followed by passage of a nitrogen stream and adsorption by activated charcoal (798). Activated carbon, which had been oxidized with nitric acid, has been used to extract several metals including divalent nickel, cadmium, cobalt, zinc, manganese, and mercury from fresh water, brine, and seawater (799, 200). 

In a 500-cc. round-bottom flask fitted with a reflux condenser are placed 68 g. of phenylurea (0.5 mole) (Note i) and 120 cc. (i mole) of 42 per cent hydrazine hydrate solution (Note 2). The flask is heated on a steam bath for about twelve hours. The hot mixture is treated with a small amount of decolorizing charcoal (Norite) and filtered. The charcoal is washed with two 15-CC. portions of warm water and the filtrate and washings are then concentrated on a steam bath to about 100 cc. On coolipg in an ice bath a crop of crystals separates and is collected on a filter and washed with two 15-cc. portions of cold water. The filtrate and washings are concentrated to about 25 cc. and another crop of crystals is obtained as before. The total yield of crude compound is 47-52 g. It is white at first but sometimes turns brown on drying. It usually melts below 115° because of some unchanged phenylurea. 

Methyl 3-aminopyrazine-2-carhoxylate [16298-03-6] M 153.1, m 169-172°, 172°. Forms yellow needles from H2O (100 parts using charcoal). If it contains the free acid then dissolve in CH2CI2 wash with saturated aqueous Na2C03, brine, dry over MgS04 filter, evaporate and recrystallise the residue. Th free acid has m 203-204° (dec) [UV Brown and Mason J Chem Soc 3443 7956] and pK <1 and pK2 3.70. The ammonium salt has m 232° (dec) (from aq Me2CO) and the amide has m 239.2° (from H2O) [Ellingson et al. J Am Chem Soc 67 1711 1945 ]. 

Ninhydrin (1,2,3-triketohydrindene hydrate) [485-47-2] M 178.1, m 241-243 (dec), pK 8.82. Crystd from hot water (charcoal). Dried under vacuum and stored in a sealed brown container. 

Nitric oxide combines readily with atmospheric oxygen at ambient temperature to produce brown fumes of pungent nitrogen dioxide, and in the presence of charcoal with chlorine to form nitrosyl chloride ... 

Tyrosine.—On cooling, a brown, crystalline crust of impure tyrosine separates. It is filtered, dissolved in the least quantity of boiling water, boiled with a little animal charcoal, and filtered. Oit cooling, long, white, silky needles of tyrosine arc deposited. Yield. rborit 2 grams. 

In the final production preparation, a mixture of ethyl methyl(3-benzoylphenyl)cyano-acetate (48 g), concentrated sulfuric acid (125 cc) and water (125 cc) is heated under reflux under nitrogen for 4 hours, and water (180 cc) is then added. The reaction mixture is extracted with diethyl ether (300 cc) and the ethereal solution is extracted with N sodium hydroxide (300 cc). The alkaline solution is treated with decolorizing charcoal (2 g) and then acidified with concentrated hydrochloric acid (40 cc). An oil separates out, which is extracted with methylene chloride (450 cc), washed with water (100 cc) and dried over anhydrous sodium sulfate. The product is concentrated to dryness under reduced pressure (20 mm Hg) to give a brown oil (33.8 g). 

Thebaine is dissolved in aqueous formic acid and treated with 30% HjO neutralization with aqueous ammonia gives 14-hydroxycodeinone. It is hydrogenated to give oxycodone. 90 ml of concentrated hydrobromic acid are heated to 90°C. 9 grams of 14-hydroxydi-hydrocodeinone (oxycodone) are then added under stirring and the mixture is quickly heated to 116°C and kept at this temperature under reflux condenser for 20 minutes, with continued stirring. The resulting brown solution Is diluted with about 90 ml of water and chilled with ice. Aqueous 10% sodium hydroxide solution is now added to alkaline reaction and the liquid is extracted 3 times with 100 cc portions of chloroform. The layers are separated and the aqueous phase is fiitered and acidified by the addition of concentrated aqueous hydrochloric acid, treated with charcoal and filtered. 

A solution comprising 3,24 kg (23.3 mols) of pyridine-2,6-dimethanol in 35 liters of pure pyridine was added to the residue and the mass was heated to 80°C for 2 /a hours. The reaction mass became brown in color. The chlorhydrate of pyridine so formed was cooled and crystallized. The resulting reaction mass was then poured into water. The precipitate obtained was filtered, repeatedly rinsed with water, and dissolved in 400 liters of methanol. The resulting solution was filtered with activated charcoal. From this filtration 50 liters of methanol were distilled at normal pressure and then crystallized. 8.35 kg (15.8 mols) of pyridine-2,6-dimethanol trimethoxybenzoate were obtained, which represented a yield of 68%. 

The slightly yellowish (almost colorless) filtrate is discarded and the charcoal residue Is washed several times with distilled water and finally with 95% ethanol. The washed material is then suspended in 1.5 liters of 95% ethanol, made 0.15 normal with hydrochloric acid. The suspension is stirred for about an hour and allowed to stand in the cold for about 10 hours more with occasional stirring. The suspension is then filtered, the charcoal residue discarded, and the yellowish clear filtrate thus obtained is poured into 10 liters of ether, with stirring. A brown-colored aqueous layer separates and is drawn off. 

Optimum toxin production was found in a stirred, aerated culture medium consisting of potato infusion and sucrose after 3 to 5 days growth. The toxin was adsorbed on charcoal from the culture filtrate and eluted with chloroform. The red-brown residue remaining after evaporation showed little or no absorption in the carbonyl region of the infrared and only weak absorption in the ultraviolet. However, on mild treatment with acid, base, or heat two carbonyl peaks appeared at 1715 and 1685 cm.-1 in the infrared and at 266 mft in the ultraviolet (3). 

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