Cyanides cuprous cyanide

Potassium cupro-cyanide is the most convenient form in which cuprous cyanide can be used in Sandmeyer s Reaction. It is prepared by adding an excess of potassium cyanide to copper sulphate solution, whereby the cupric cyanide which is formed immediately breaks down to give cuprous cyanide and cyanogen, and the cuprous cyanide then dissolves in the excess of potassium... 

Cuprous cyanide. Method 1 (Barber, 1943). This is based essentially upon the reaction ... 

Cuprous cyanide solution. The most satisfactory method is to dissolve the cuprous cyanide (1 mol) in a solution of technical sodium cyanide (2 5-2-6 mols in 600 ml. of water). If it is desired to avoid the preparation of solid cuprous cyanide, the following procedure may be adopted. Cuprous chloride, prepared from 125 g. of copper sulphate crystals as described under 1 above, is suspended in 200 ml. of water contained in a 1-litre round-bottomed flask, which is fitted with a mechanical stirrer. A solution of 65 g. of technical sodium cyanide (96-98 per cent.) in 100 ml. of water is added and the mixture is stirred. The cuprous chloride passes into solution with considerable evolution of heat. As the cuprous cyanide is usually emplo3 ed in some modification of the diazo reaction, it is usual to cool the resulting solution in ice. 

It has been stated that many halogen-free compounds, e.g., certain derivatives of pyridine and quinoline, purines, acid amides and cyano compounds, when ignited on copper oxide impart a green colour to the dame, presumably owing to the formation of volatile cuprous cyanide. The test is therefore not always trustworthy. The test is not given by duorides. 

Allyl cyanide. Into a 1 5 litre three-necked flask (1), provided with a mercury-sealed stirrer and two long double surface condensers, place 293 g. (210 ml.) of freshly-distilled allyl bromide, b.p. 70-71° (Section III, 35) and 226 g. of dry cuprous cyanide (Section 11,50,3, Method 1), Remove the mercury-sealed stirrer and replace it by a tightly fitting... 

The Sandmeyer reaction may also be applied to the preparation of nitriles. The solution of the diazonium salt is added to a solution of cuprous cyanide in excess of sodium or potassium cyanide solution (sometimes improved yields are obtained by substituting nickel cyanide for cuprous cyanide), for example CH3 CH, CH3... 

Benzonitrile (phenyl cyanide). Prepare a cuprous cyanide solution in a 500 ml. round-bottomed flask as above, but use the following quantities 65 g. of crystallised copper sulphate in 205 ml. of water, 18 g. of sodium bisulphite in 52 ml. of water, and 18 g. of potassium cyanide in... 

By the hydrolysis of nitriles. The nitriles may be easily prepared either from amines by the Sandmeyer reaction (Section IV,66) or by the action of cuprous cyanide upon aryl halides (compare Section IV,163). Benzyl cyanide... 

Method 1. a-Naphthonitrile. Place 80 g. (54 ml.) of redistilled a-bromonaphthalene (Section IV.20), 43 g. of dry powdered cuprous cyanide (Section II,50,J) and 36 g. (37 ml.) of dry pure pyridine (1) (Section 11,47.22) in a 250 ml. round-bottomed flask fitted with a ground-in reflux condenser carrying a calcium chloride (or cotton wool) guard tube, and heat the mixture in a metal bath at 215-225° for... 

By heating halogenated benzenes or naphthalenes with cuprous cyanide, for example, a-naphthonitrile from a-bromonaphthalene and cuprous cyanide (Section IV,163). 

The patended method of preparation of the blue dye (120) [19187-01 -0] (81) involves treating the analogous dibromo substituted azo dye with cuprous cyanide in dimethylformamide or A-methylpyrrohdinone at 50°C to effect replacement of the two bromo substituents by cyano groups. 

The greenish-blue dye (117) (82) is prepared in a similar fashion, replacing bromo with cyano by using cuprous cyanide, pyridine, and 2-methoxyethanol as solvent at 85°C. 

Chloro-l,2-benzisothiazole reacts with sodium cyanide to give a mixture containing mainly o-cyanophenyl thiocyanate with some di-(o-cyanophenyl) disulfide. An 80% yield of the latter was obtained using cuprous cyanide in DMF (73SST(2)556). 

Terephthalic acid has been obtained from a great many /)-disubstituted derivatives of benzene or cyclohexane by oxidation with permanganate, chromic acid, or nitric acid. The following routes appear to have preparative value from />-toluic acid, />-methylacetophenone,2 or dihydro-/)-tolualdehyde by oxidation with permanganate from f>-cymene by oxidation with sodium dichromate and sulfuric acid from />-dibromobenzene or from /i-chloro- or -bromobenzoic acid by heating at 250° with potassium and cuprous cyanides and from />-dibromo-benzene, butyllithium, and carbon dioxide. ... 

Cuprous cyanide [544-92-3] M 89.6, m 474°. Wash thoroughly with boiling H2O, then with EtOH. Dry at 100° to a fine soft powder. [J Chem Soc 79 1943.]... 

Another process using butadiene as the starting material was developed by Esso. This involved the reaction of butadiene with iodine and cuprous cyanide to give the cuprous iodide complex of dehydroadiponitrile. This is further reacted with HCN to give a high yield of dehydroadiponitrile and regeneration of the iodine and cuprous iodide. 

Chemical Designations - Synonyms Cupricin Cuprous Cyanide Chemical Formula CuCN. Observable Characteristics - Physical State (as normally shipped) powder Color white Odor Data not available. 

Methoxythiophene and 3-cyanothiophene have been prepared from 3-bromothiophene by means of a cupric oxide-catalyzed Williamson synthesis and by reaction with cuprous cyanide in quinoline, respectively. 

Halogeno compounds have been prepared by direct halogena-tion or by Sandmeyer reaction on 4-aminoisothiazoles. As expected from general considerations, a halogen atom in the 4-position is less reactive than one in the 5-position, but nitriles are obtained in good yield with cuprous cyanide at elevated temperatures. With butyllithium, lithiation occurs exclusively in the 5-position, and no evidence of halogen displacement has been obtained. ... 

Cupro-. cuprous, copper(I), cupro-. -chlorid, n. cuprous chloride, copper(I) chloride, -cy-aniir, n. cuprous cyanide, copper(I) cyanide cuprocyanide, cyanocuprate(I). -jodid, n. cuprous iodide, copper(I) iodide, -mangan, n. cupromanganese. -oxyd, n. cuprous oxide, copper(I) oxide, -salz, n. cuprous salt, cop-per(I) salt, -suifocyantir, n. cuprous thiocyanate, copper (I) thiocyanate, -verbin-dUDg, /. cuprous compound, copper(I) compound. 

Kupfer-bromid, n. copper bromide, specif, cupric bromide, copper(II) bromide, -bro-mtir, n. cuprous bromide, copper(I) bromide, -chlorid, n. copper chloride, specif, cupric chloride, copper(II) chloride, -chloriir, n. cuprous chloride, copper(I) chloride, -cyamd, Ti. copper cyanide, specif, cupric cyanide, copper(II) cyanide, -cyaniir, n. cuprous cyanide, copper(I) cyanide, -dom, m. slag from liquated copper, -draht, m. copper wire, -drahtnetz, n. copper gauze, -drehspane,... 

Cuprous cyanide Ethyl bromide Potassium bisulfate Sodium hydroxide... 

Fluocortin butyl Cupric cyanide Cyamemazine Cuprous chloride Halo progin Cuprous cyanide Methallenestrll Curare... 

A. Preparation of Cuprous Cyanide. (Note i)—In a 6-1. round-bottom flask fitted with a stopper carrying a mechanical stirrer, a separatory funnel, and a gas exit tube leading to a good hood (Note 2), is placed a solution of 650 g. (2.6 moles) of crystallized copper sulfate in 4 1. of water. The flask is surrounded by an oil bath and heated to about 8o°. The stirrer is started and a solution of 255 g. (5.2 moles) of sodium cyanide (Note 3) in 650 cc. of water is added from the separatory funnel over a period of about one-half hour. Then the mixture is boiled until no more cyanogen gas is evolved. This requires about five to ten minutes. 

The cuprous cyanide, which begins to separate as a light tan precipitate as soon as any of the cyanide solution is added, is allowed to settle and the solution is decanted. The precipitate is filtered, then washed with water (r 1.) and finally with alcohol (500 cc.) and ether (300 cc.). After drying at no0 for about thirty-six hours, the product weighs 200-210 g. (85-90 per cent of the theoretical amount). 

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