Bromine cyanogen

The use of copper salts and of copper itself for the replacement of the diazo-group of aromatic compounds, by chlorine, bromine, cyanogen, otc., is important. 

Little preparative importance attaches to conversion of organic sulfides into chloro compounds The fission of compounds R-S-R by chlorine, bromine, cyanogen bromide, and methyl iodide, with replacement of C-S by C-halogen bonds has been reviewed by Tarbell and Harnish.1287 The action of 1 mole of bromine on thioacetals in an anhydrous medium (ether) at room temperature affords bromo hemiacetals (a-bromo sulfides) and a sulfenyl bromide, and bromo sugars analogously from ethyl thioglycosides. 

Treatment of quinoline with cyanogen bromide, the von Braun reaction (17), in methanol with sodium bicarbonate produces a high yield of l-cyano-2-methoxy-l,2-dihydroquinoline [880-95-5] (5) (18). Compound (5) is quantitatively converted to 3-bromoquinoline [5332-24-1], through the intermediate (6) [66438-70-8]. These conversions are accompHshed by sequential treatment with bromine in methanol, sodium carbonate, or concentrated hydrochloric acid in methanol. Similar conditions provide high yields of 3-bromomethylquinoHnes. 

Upper and lower respiratory Eluorine chlorine bromine ozone cyanogen chloride. ... 

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... 

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,... 

Brom-benzol, n. bromobenzene. calcium, n. calcium bromide, -cyan, n. cyanogen bromide, bromocyanogen. -dampf, tn. bromine vapor, -eisen, n. iron bromide, -fiasche, /. bromine bottle, -fluor, n. bromine fluoride, -gehalt, tn. bromine content, -gold, n. gold bromide, -goldkalium, n. potassium auri-bromide, potassium bromoaurate. bromhaltig, a. contaim ng bromine, Brom-hydrat, n. hydrobromide bromine hydrate. -hydrin, n. bromohydrin. 

Fluorine chlorine bromine ozone cyanogen chloride. 

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. 

A second method is due to J. von Braun and consists in the addition of cyanogen bromide to tertiary cyclic bases.1 In the unstable addition product a C—N-linkage is broken and at the same time the bromine wanders to a new position. A brominated derivative of cyanamide is produced and this, on hydrolysis, yields a secondary amine which can be broken down further, e.g. 

Bromine azide, 0256 Chlorine azide, 4030 Cyanogen azide, 0544 Fluorine azide, 4307 Iodine azide, 4621 See metal pnictides... 

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

A few syntheses of specific substituted 3,3 -bipyridines have been reported. 6,6 -Dialkyl-3,3 -bipyridines have been shown to be one of the products of the reaction of l-lithio-2-alkyl-l,2-dihydropyridines with perhalometh-anes, cyanogen bromide, or bromine. In an interesting double... 

The formadon of alkynenitriles from alkynylmagnesium halides and cyanogen chloride was described far die fust tune by Grignard [114], A number of these nitriles have been prepared in our laboratory from alkynyllithium and cyanogen chloride using I O as a solvent [115], Cyanogen bromide is unsuitable because the alkynylide attacks on bromine [2],... 

A convenient and quick way to prepare 1-bromoalkynes consists of adding an ethereal solution of cyanogen bromide to a strongly cooled solution of a metallated (Li or MgX) [119] acetylene in an organic solvent (EtjO or THF). The method seems very general and excellent yields can be obtained provided that the ethereal solution of BrC N (which is prepared from an aqueous solution) is dried well. The advantage of this method over the introduction with elemental bromine is that CC double bonds in the acetylenic compounds do not react... 

Syntheses of 5-halogenotetrazoles from metallic derivatives have met with mixed fortunes. Lithiation of 1-methyltetrazole followed by reaction at -60°C with bromine, iodine, or cyanogen bromide gave the 5-bromo and 5-iodo compounds in 36-55% yields (71CJC2139). 1,2-Disubstituted tetrazolium tetraphenylborates were lithiated in the 5-position, but subsequent reaction with chlorine or bromine failed to trap the anion. Instead, oxidation produced a radical cation, which abstracted a hydrogen atom from the solvent [91 AG(E)1162]. 

These ethers are produced bj the substitutioa of hydroxyl in the alcohols by chlorine, bromine, iodine, fluorine, or cyanogen. 

Silver cyanide acts on a benzene solution of the tetrabromide, replacing bromine by the cyanogen radical, with simultaneous reduction, the product being a solid tellurium dicyanide ... 

Cyanogen, Chlorine, and Bromine.—Shake 0.5 gm. of powdered iodine with 20 cc. of water, and filter. To 10 cc. of the filtrate, add, drop by drop, decinormal sodium thiosulphate solution until decolorized, then add a granule of ferrous sulphate, 1 drop of ferric chloride solution and 2 cc. of sodium hydroxide solution. Warm to about 60° C., and add 10 cc. of hydrochloric acid. The liquid should not acquire a blue color. Filter, and to 10 cc. of the filtrate add 1 cc. of ammonia water, 5 drops of silver nitrate solution, and again filter. On adding to the filtrate 2 cc. of nitric acid no precipitate, and not more than an opalescent turbidity, should develop. ... 

---