Cyanogens bromide

Cyanogen chloride and cyanogen bromide in drinking water may be analyzed by GC-ECD. Saturated headspace is injected onto a capillary column for analysis (Xie and Reckhow 

Cancho et al. (2000) have described a headspace solid-phase microextraction for separation of cyanogen halides from water followed by their GC-ECD detection. 

Cyanogen chloride can be destroyed in an incinerator. It is dissolved in a combustible solvent and burned. 

EPA Classified Toxic Waste, RCRA Waste Number U246 DOT Label Poison and Corrosive UN 1889 

Synonyms bromine cyanide bromocyanide bromocyan bromocyanogen cyanobro-mide Campilit 

---

Compare the dipole moments of cyanogen bromide (BrC=N) and cyanogen chloride (C1C=N) Which IS larger" Why" What does this tell you about the electronegativity of the CN group" ... 

Nitrile Synthesis. Cyanogen bromide [506-68-3] condenses with toluene in the presence of aluminum chloride to give -tolunittile (129). 

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. 

The N-oxides of isoquinolines have proved to be excellent intermediates for the preparation of many compounds. Trialkylboranes give 1-alkyl derivatives (147). With cyanogen bromide in ethanol, ethyl N-(l- and 4-isoquinolyl)carbamates are formed (148). A compHcated but potentially important reaction is the formation of 1-acetonyLisoquinoline and 1-cyanoisoquinoline [1198-30-7] when isoquinoline N-oxide reacts with metbacrylonitrile in the presence of hydroquinone (149). Isoquinoline N-oxide undergoes direct acylamination with /V-benzoylanilinoisoquinoline salts to form 1-/V-benzoylanilinoisoquinoline [53112-20-4] in 55% yield (150). A similar reaction of AJ-sulfinyl- -toluenesulfonamide leads to l-(tos5larriino)isoquinoline [25770-51-8] which is readily hydrolyzed to 1-aminoisoquinoline (151). 

H. A. Hageman, "The Von Braun Cyanogen Bromide Reaction," in R. Adams and co-workers, eds.. Organic Reactions, Vol. 7, John Wiley Sons,... 

The Kixnig reaction (Fig. 5) has been used to determine the amount of nicotinic acid and niacinamide. In this procedure, quatemization of the pyridine nucleus by cyanogen bromide is followed by ring opening to generate the putative dialdehyde intermediate. Reaction of this compound with an appropriate base, such as p-rr ethyl am in oph en o1 sulfate (47) or sulfanilic acid (48), generates a dye. The concentration of this dye is deterrnined c olo rime trie ally. 

Deall lation. Chloroformates such as vinyl chloroformates (40) are used to dealkylate tertiary amines. Chloroformates are superior to the typical Von Braun reagent, cyanogen bromide, because of increased selectivity producing cleaner products. Other chloroformates such as aHyl, methyl, phenyl, and trichloroethyl have also been used in dealkylation reactions. Although the dealkylation reaction using chloroformates is mostiy carried out on tertiary amines, dealkylation of oxygen or sulfur centers, ie, ethers or thioethers, can also be achieved. a-Chloroethyl chloroformate [50893-53-3] (ACE-Cl) (41,42) is superior to all previously used chloroformates for the dealkylation reaction. ACE-Cl has the advantage that the conditions requked for ACE... 

Additional pyrimido[4,5-f ]quinoline syntheses include one involving the action of cyanogen bromide on 2-chloro-3-cyanoquinoline similar to that described for pyridines (Section 2.15.5.5.1) (78JHC877), and a synthesis of pyrimido[4,5-fe]quinoline-2-carboxylic... 

Azoles can form stable compounds in which metallic and metalloid atoms are linked to nitrogen. For example, pyrazoles and imidazoles Af-substituted by B, Si, P and Hg groups are made in this way. Imidazoles with a free NH group can be Af-trimethylsilylated and Af-cyanated (with cyanogen bromide). Imidazoles of low basicity can be Af-nitrated. 

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... 

Copper amine azide Copper tetramine nitrate Crotonaldehyde, stabilized Cyanogen bromide Cyanuric triazide... 

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

A number of other syntheses of coniine have been effected, of which that of Diels and Alder is of special interest. The initial adduct of pyridine and methyl acetylenedicarboxylate, viz., tetraraethylquinolizine-1 2 3 4-tetracarboxylate (IX) on oxidation with dilute nitric acid is converted into methyl indolizinetricarboxylate (X). This, on hydrolysis and decarboxylation, furnishes indolizine, the octahydro-derivative (XI) of which, also known as octahydropyrrocoline, is converted by the cyanogen bromide method (as applied by Winterfeld and Holschneider to lupinane, p. 123) successively into the broraocyanoamide (XII), cyanoaraide (XIII) and dZ-coniine (XIV). A synthesis of the alkaloid, starting from indolizine (pyrrocoline) is described by Ochiai and Tsuda. ... 

The same authors have investigated the degradation of lupinane (XIII), cf. (XIV), by the cyanogen bromide process, the steps and products being as follows —... 

Dendrobine methiodide is convertible into the methohydroxide, m.p. 251° dec.). With cyanogen bromide cyanonordendrobine, m.p. 188°, was obtained, from which nordendrobine, m.p. 117-8°, — 21-6°... 

---