Barium cyanide production

In 1895, Frank and Caro found that when barium carbide was heated to redness in air the main product was barium cyanide, but simultaneously a certain amount of barium cyanamide was formed. These two reactions, therefore, proceeded side by side ... 

Discarded commercial chemical products off-specifications species container residues, and spill residues thereof Barium cyanide Yes... 

It has been mentioned (p. 13) that D-manno-o-tolo-heptitol is identical with natural voleraitol. If -one desires a supply of voleraitol, probably the best procedure at the present time is its synthetic production from D-mannose even though the D-manno-D-synthetic method appears to be more practicable than the isolation of the alcohol in quantity from known natural sources. The use of barium cyanide or the equivalent mixture of a barium salt and sodium cyanide, in place of hydrocyanic acid appears to favor the yield of the desired heptonic acid. On the other hand, the possibility of starting with o-altrose, which is now no longer a particularly rare sugar, appears of interest because the desired heptose (D-altro-D-mormo-heptose) should be the major product in that series if the generalizations that have been presented hold for altrose. This speculation has been offered because it seems to the writer that many carbohydrates that are now only laboratory curiosities, can be made at costs that are not prohibitive for the use of them in exploratory researches, especially in the bacteriological, physiological and biochemical fields. 

Metyrosine Metyrosine, (-)a-methyltyrosine (12.3.11), is synthesized in a few different ways, the simplest of which is the synthesis from 4-methoxybenzylacetone, which is reacted with potassium cyanide in the presence of ammonium carbonate to give the hydan-toin (12.3.9). Treating this with hydrogen iodide removes the methyl-protecting group on the phenyl hydroxyl group and the product (12.3.10) is hydrolyzed by barium hydroxide into a racemic mixture of a-methyl-D,L-tyrosine, from which the desired L-isomer is isolated (12.3.11) [83-86]. 

Hydrofluoric acid like water is an associated liquid, and even the gas, as we shall soon see, is associated. It has the power of uniting with fluorides. It also seems to be an ionizing solvent for a soln. of potassium fluoride in liquid hydrogen fluoride is an excellent conductor it also possesses marked solvent powers. According to E. C. Franklin,7 the liquid readily dissolves potassium fluoride, ehloride, and sulphate sodium fluoride, bromide, nitrate, chlorate, and bromate acetamide and urea. The solvent action is not so marked with barium fluoride, cupric chloride, and silver cyanide while calcium and lead fluorides copper sulphate and nitrate ferric chloride, mercuric oxide, and magnesium metal, are virtually insoluble in this menstruum. Glass also is not affected by the liquid if moisture be absent. The liquid scarcely acts on most of the metals or non-metals at ordinary temp., though it does act on the alkali metals at ordinary temp., much the same as does water, with the simultaneous production of flame. 

Sodium, potassium, barium, or calcium thiocyanate may be made by reaction of sulfur and the corresponding cyanide by heating to fusion. Ammonium thiocyanate (plus ammonium sulfide) may be made by reaction of ammonia and carbon disulfide, a reaction which probably accounts for tlie presence of ammonium thiocyanate in the products of the destructive distillation of coal. This reaction corresponds to the formation of ammonium evanate from ammonia and carbon dioxide. 

Tho by-product of the first stage, barium cyananude, is separated from the cyanide and converted into alkali cyanido by fusion with carbonate ... 

The first examples reported by Sandmeyer date back to 1884. The many various preparative procedures differ mainly in the type and the preparation of the copper-cyanide complex which is used. In the Gattermann procedure KCN in the presence of Cu powder is used. Generally one tries to avoid the formation of HCN on the addition of alkali metal cyanide to the acidic medium by neutralizing the diazo-nium salt solution in advance with sodium or barium carbonate. Cyanogen, which is formed from CN ions on treatment with Cu" salts, is also a harmful by-product. In this case the addition of sodium hydrogen sulfite (equation 19) proved to be of great value. 

Following the procedure described by Reutov and Shatkina (10), reaction of 1,5-dibromopentane with 90% 13C-enriched potassium cyanide provided the 1,5-dicyanide which was hydrolyzed to pimelic acid in aqueous hydrochloric acid (pure in 65% yield). This acid was then reacted with barium carbonate and the product was heated at 340° under distilling conditions for 4 hrs (10). 

The carbon dioxide content of the product is reduced by adding barium chloride to the cyanide solution and removing precipitated barium carbonate. 

In applying the Kuhn methylation to a pentasaccharide isolated from amylopectin a-limit dextrin, the maximum methoxyl content that French, E. E. Smith, and Whelan were able to obtain was 41.8X (theoretical, 49.5%). Quantitative analysis of the hydrolyzate showed that there was no undermethylation, and they concluded that it is essential to wash the product with cyanide after each methylation in order to eliminate chloroform-soluble impurities containing iodine. Kabat and coworkers found that a Kuhn methylation of hexosamines using silver oxide did not give interpretable results, but no problem was experienced when barium oxide was employed. 

Write a balanced equation for each of the following reactions (a) Hydrogen cyanide is formed commercially by passing a mixture of methane, ammonia, and air over a catalyst at 800 °C. Water is a by-product of the reaction, (b) Baking soda reacts with acids to produce carbon dioxide gas. (c) When barium carbonate reacts in air with sulfur dioxide, barium sulfate and carbon dioxide form. 

The reaction of hydroxyl dehydration, which eliminates the chain terminal hydroxyl is a drawback in the case of production of polyols for polyurethane industry, therefore several catalysts apart from potassium and sodium hydroxide have been proposed. These catalysts, including hydroxide of rubidium, cesium, barium and strontium, or double metal cyanide, are much more expensive and toxic than classical catalysts [11], Recently, a new class of catalyst has been... 

White silver cyanide, thiocyanate, ferro- and yellow ferricyanide are decomposed with production of ignition-resistant silver. All metal ferro- and ferricyanides of the base metals leave a residue of ferric oxide and the particular metal oxide. For instance, the colorless ferrocyanides of zinc, cadmium, magnesium, calcium, barium, strontium, thorium etc. become yellow-brown Prussian blue and Turnbull s blue become dark (Fe304) and, later, brown (FegOg). Cupric ferricyanide (brown) and cupric ferrocyanide (violet-brown) are blackened when ignited because of the formation of cupric oxide. 

The most common salt of trade and utility is K CN. A convenient and safe method of preparation on a scale of 1-10 mmol is reduction of barium [ CJcarbonate with potassium azide at elevated temperatures the procedure is highly reproducible and gives radiochemical yields in the range of 90-98% . In this procedure an intimate mixture of barium [ C]-carbonate, potassium azide and carefully dried sea sand is heated at temperatures slowly increasing from 450 to 700 °C. The resulting crude product is acidified with 85% phosphoric acid, and H CN released is expelled with helium into a methanolic solution of potassium methoxide, from which the K CN is isolated in solid form by evaporation of the solvent. (Caution HCN is volatile and extremely toxic.) Sodium [ C]cyanide can be prepared the same way, except using methanolic sodium methoxide. Potassium [ " C]-cyanide is indefinitely stable as a dry solid at ambient temperature the sodium salt is somewhat less so. 

In 1895 Adolf Frank (1834-1916) and Nikodemus Caro (1871-1935) substituted barium carbide for the carbonate and reported that the reaction proceeded better with addition of water vapor. In contrast, shortly afterward F. Rothe, employed by Beringer Sohne in Charlottenburg found that the reaction proceeds best with very pure Nz and in the driest possible conditions. In 1898, after Rothe began working for Frank and Caro in Hamburg, he discovered that cyanamide, rather than cyanide, was the main product. Once it was shown that a much cheaper calcium carbide reacts in much the same way at temperatures between 1,000 and 1,100 °C, it was possible to contemplate a commercial venture based on the reaction... 

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