Cyanides cyanogen bromide

Cyanogen bromide, Bromide cyanide Cyanogen bromide, Bromide cyanide l-Bromo-2-propanone Biguanide diperchlorate... 

Electrolysis of dilute solutions of hydrogen cyanide in ammonium bromide to give cyanogen bromide. This is then dissolved in a solvent such as tetrahydrofuran and reacted with gaseous ammonia to produce cyanamide. The cyanamide is then heated in an autoclave at about 190-200°C in the presence of ammonia and the melamine, recovered by filtration. 

Cyanogen bromide (Bromine cyanide) CNBr Extremely irritating and toxic vapours Contact with acids, acid fumes, water or steam can produce toxic and corrosive fumes Transparent crystals with a penetrating odour Melting point 52°C Boiling point 61 °C Vapour density 3.6 Water soluble... 

Cyanogens Cyanogens Hydrogen cyanide Cyanogen chloride Cyanogen bromide Cyanogen iodide Acetonitrile Acrylic nitrile... 

The solid disulfide reacts explosively with chlorine or bromine. At low temperatures in certain non-aqueous solvents, e.g. chloroform, CISCSN3 and BrSCSN3 are probably formed, but the extreme instability of these compounds has precluded their exact analysis and description. However, the reaction between cyanogen bromide and the potassium salt of the thiol yields the well-defined cyanide NCSCSN3,... 

Cyan-Mthert m. cyanic ester. -Mthyl, n. ethyl cyanide, -bad, n. cyanide bath. -baryum,n. barium cyanide, -benzol, n. cyanobenzene. -bromid, n. cyanogen bromide, -calcium, n. calcium cyanide, -chlorid, n. cyanogen chloride. -doppelsalZt n. double cyanide. 

Cyanide and thiocyanate anions in aqueous solution can be determined as cyanogen bromide after reaction with bromine [686]. The thiocyanate anion can be quantitatively determined in the presence of cyanide by adding an excess of formaldehyde solution to the sample, which converts the cyanide ion to the unreactive cyanohydrin. The detection limits for the cyanide and thiocyanate anions were less than 0.01 ppm with an electron-capture detector. Iodine in acid solution reacts with acetone to form monoiodoacetone, which can be detected at high sensitivity with an electron-capture detector [687]. The reaction is specific for iodine, iodide being determined after oxidation with iodate. The nitrate anion can be determined in aqueous solution after conversion to nitrobenzene by reaction with benzene in the presence of sulfuric acid [688,689]. The detection limit for the nitrate anion was less than 0.1 ppm. The nitrite anion can be determined after oxidation to nitrate with potassium permanganate. Nitrite can be determined directly by alkylation with an alkaline solution of pentafluorobenzyl bromide [690]. The yield of derivative was about 80t.with a detection limit of 0.46 ng in 0.1 ml of aqueous sample. Pentafluorobenzyl p-toluenesulfonate has been used to derivatize carboxylate and phenolate anions and to simultaneously derivatize bromide, iodide, cyanide, thiocyanate, nitrite, nitrate and sulfide in a two-phase system using tetrapentylammonium cWoride as a phase transfer catalyst [691]. Detection limits wer Hi the ppm range. 

The von Braun reaction (Scheme 6) is another basic reaction for C—N bond cleavage 32). Tetrahydroberberine (26) was heated under reflux with cyanogen bromide in benzene to afford the bromocyanide (28) and the unsaturated cyanide (29) through C-6—N and C-14—N bond cleavage, respectively. The C-8—N bond cleavage product was not obtained because of the steric hindrance of the methoxyl group at C-9 in SN2-type reactions 33). The... 

Cyanogen bromide is moderately endothermic (AH°f (g) +50 kJ/mol, 0.47 kJ/g) and shows evidence of instability. The plastic cap of a bottle stored in a laboratory for several years on a high shelf, occasionally at 31°C, shattered and drove fragments into the shelf above [1]. This instability was confirmed, and a procedure outlined to obviate the use of the bromide in autoanalysis by generating cyanogen chloride on demand from Chloramine-T and potassium cyanide [2], A 50 wt% solution of the bromide in chloroform is a stable and convenient form for use [3], See Cyanogen chloride... 

Cyanogen bromide is used in organic synthesis, as a rodent poison, and as a reagent for extracting gold as its cyanide salt. 

Cyanogen bromide is obtained by the reaction of bromine with potassium cyanide or sodium cyanide ... 

Methenamine Trivinylarsenic Trisvinylarsine Cyanogen bromide Bromide cyanide Adamsite... 

Many organic and inorganic cyanides, cyanates, isocyanates and thiocyanates react with sulfur tetrafluoride at elevated temperatures with the formation of iminosulfur difluorides. Thus, cyanogen bromide, sodium cyanide, and sodium thiocyanate give (trifluoromethyl)imino-sulfur difluoride (1) in 37 -70% yield.202... 

Cyanogen bromide has been prepared from an aqueous solution of potassium cyanide and bromine at o 3,1 and by the action of bromine on moist mercuric cyanide.2... 

Harris et al. [8] has described methods for the determination of cyanide in these materials based on either spectrophotometry using p-phenylene diamine pyridine or gas chromatographically following conversion of cyanide to cyanogen bromide. Cyanide is extracted from the sample by digestion with phosphoric acid. Recoveries were in the range 96-99% (spectrophotometric method) and 90-96% (gas chromatographic method). 

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