Cyanogen bromide iodide

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

Although cyanogen iodide or cyanogen bromide adds to pentafluoropropene-2-ol to produce the halocyanohydnns, cyanogen chlonde is unreactive [75] (equation 44)... 

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. 

Cyclization of 167 with ethyl orthoformate leads to 176 (R = H, 36%). With cyanogen bromide in refluxing methanol 176 (R = NH2) is obtained in only 10% yield. Reaction of 167 with carbon disulfide (methanol, H2O, KOH, reflux) leads to the 5-methylthiazolo[3,2-6][l,2,4]triazole-2-thiol (176, R = SH), which was readily converted to 176 (R = SMe) with methyl iodide [76JHC(13)1225]. 

While the reaction of MFA with cyanogen bromide (BrCN) in refluxing chloroform caused ring fission to yield 3 [Fig. (4)], under the same conditions cyanogen iodide did not provide the iodo analog 13. 

E-alkenes 81 can also be obtained349 by treatment of 78 (R" = H) with cyanogen bromide or cyanogen iodide in CH2Cl235(l or with Pd(OAc)2-Et3N.351... 

Photosolvolysis of quaternary iodides 77, and the reaction of 2,3,4,6, 7,llh-hexahydro[l,3]oxazino[2,3-b]isoquinoline (79) with cyanogen bromide afforded 2,6-benzoxazecines 78 and 80, respectively [79CI(L)319 80CI(L)421 85AJC1591 86AJC893]. 

Also, in the halogenation of XXb with cyanogen bromide the predominate product was the nortricyclenic bromide (XXIIIa and b, X = Br) the treatment of XXIa with iodine monochloride yields the endo-nortricyclenic iodide (XXIIIa, X = I). Thus the mechanism appears to involve attack of a positive halogen with predominate retention of configuration at carbon. 

Addition of cyanogen bromide or iodide instead of halogen gives the tricyanohalophosphates(III), X = Br, I. 

From Diaryl Tellurium and Cyanogen Bromide or Cyanogen Iodide... 

Other methods were developed for various anions. Bromides were oxidized with permanganate and the bromine so produced reacted with cyclohexene to form 1,2-dibromocyclohexane [577]. Similarly, iodides were analysed in milk as monoiodoacetone after oxidation with iodate and after reaction of the released iodine with acetone [578]. Pennington [579] utilized the same oxidation reaction for the analysis of iodates the iodine released was analysed as such. Cyanides were chlorinated prior to analysis with chloramine-T and the cyanogen chloride so produced was subjected to GC [580]. Analogously, cyanides and isocyanates form cyanogen bromide with bromine water, which can be analysed by GC [581]. 

In contrast to haplophytine, cimicidine does not react with cyanogen bromide, nor with neutral potassium permanganate at room temperature. Reaction with methyl iodide leads to a quaternary salt,... 

Kurtenacker2 found that cyanogen bromide and iodide react with sodium thiosulphate in neutral solution in accordance with the equation... 

IODIDES Triphenylphosphite methiodide. ISOCYANATES Cyanogen bromide. 

Suitable cleaving agents include organic halides such as primary alkyl bromides, iodides or sulfo-nates " ° allylic," - allenic and propargylic bromides vinylic or aryl halides with nickel or palladium promoters " alkyl chloroformates epoxides and even cyanogen or cyanogen bromide. Typical examples of such couplings are depicted in equations (55)-(57). 

In carrying out this determination, a weighed quantity of cyanogen bromide is treated with an excess of hydriodic acid solution, which is prepared by dissolving 10 gm. potassium iodide in 100 ml. of a 5% solution of acetic acid. The iodine liberated is titrated with a decinormal solution of sodium thiosulphate. 

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