Cyanides preparation

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... 

Aqueous solutions of calcium cyanide prepared even at low temperature turn yellow or brown owing to the formation of HCN polymer. Calcium cyanide hydroly2es readily. 

Benzyl cyanide, prepared according to Org. Syn. Coll. Vol. 1, 1941, 107, should be distilled from Raney nickel. Minute traces of halide ha - a strong poisoning effect on the catalyst. If the reduction does not occur within an hour, the contents of the bomb should be removed and filtered. New catalyst is then added and the process is repeated. 

Other approaches to tetrazoles were also recently published. Primary and secondary amines 195 were reacted with isothiocyanates to afford thioureas 196, which underwent mercury(II)-promoted attack of azide anion, to provide 5-aminotetrazoles 197 . A modified Ugi reaction of substituted methylisocyanoacetates 198, ketones, primary amines, and trimethylsilyldiazomethane afforded the one-pot solution phase preparation of fused tetrazole-ketopiperazines 200 via intermediate 199 <00TL8729>. Microwave-assisted preparation of aryl cyanides, prepared from aryl bromides 201, with sodium azide afforded aryl tetrazoles 202 . 

EPA. 1987k. Drinking Water Criteria Document for Cyanide. Prepared by the Office of Elealth and Environmental Assessment Environmental Criteria and Assessment Office, Cincinnati, OH, for the Office of Drinking Water, Washington, DC. External Review Draft. 

The benzyl cyanide, prepared according to the procedure as outlined, is collected over a 50 range. It varies in appearance from a colorless to a straw-colored liquid and often develops appreciable color upon standing. For a product of special purity, it should be redistilled under diminished pressure and collected over a 1-20 range. For most purposes, such as the preparation of phenylacetic acid or ester, the fraction boiling i35-i40°/38 mm. is perfectly satisfactory. 

In a 5-I. round-bottom flask, fitted with a mechanical stirrer and reflux condenser, are mixed 1150 cc. of water, 840 cc. of commercial sulfuric acid and 700 g. of benzyl cyanide (preparation III, p. 9). The mixture is heated under a reflux condenser and stirred for three hours, cooled slightly and then poured into 2 1. of cold water. The mixture should be stirred so that a solid cake is not formed the phenylacetic acid is then filtered off. This crude material should be melted under water and washed by decantation several times with hot water. These washings, on cooling, deposit a small amount of phenylacetic acid which is filtered off and added to the main portion of material. The last of the hot water is poured off from the material while it is still molten and it is then transferred to a 2-1. Claisen distilling flask and distilled in vacuo. A small amount of water comes over first and is rejected about 20 cc., containing an appreciable amount of benzyl cyanide, then distils. This fraction is used in the next run. The distillate boiling i76-i89°/5o mm. is collected separately and solidifies on standing. It is practically pure phenylacetic acid, m. p. 76-76.5° it amounts to 630 g. (77.5 per cent of the theoretical amount). As the fraction which is returned to the second run of material contains a considerable portion of phenylacetic acid, the yield actually amounts to at least 80 per cent. 

A somewhat similar method of cyanide preparation is applicable in the aromatic series aromatic sulphonic acid potassium salts, on fusion with potassium cyanide or potassium ferrocyanide, yield aromatic nitriles. The reaction can be extended to derivatives of pyridine. 

The preparation of zinc cyanide should be carried out in the fume cupboard and great caution exercised in the handling of the cyanides. Prepare solutions containing 100 g of technical sodium cyanide (97-98% NaCN) (CAUTION) in 125 ml of water and 150g of anhydrous zinc chloride in the minimum volume of 50 per cent ethanol (1). Add the sodium cyanide solution rapdily, with agitation, to the zinc chloride solution. Filter off the precipitated zinc cyanide at the pump, drain well, wash with ethanol and then with ether. Dry the product in a desiccator or in an air bath at 50 °C, and preserve in a tightly stoppered bottle. 

Active zinc from the lithium reduction of zinc cyanide preparation of 5-oxo-5-phenyl-(A/,/V-diisopropyl)pentamide... 

Acetone cyanohydrin has been prepared from acetone and anhydrous hydrogen cyanide in the presence of a basic catalyst such as potassium carbonate, potassium hydroxide, or potassium cyanide 1 by the reaction of potassium cyanide on the sodium bisulfite addition product of acetone 2 and by the action of hydrogen cyanide, prepared directly in the reaction mixture, on an aqueous solution of acetone.3... 

Hydtoxy ketones, dehydration, 30 preparation, 130, 131, 164, 174 Hydroxy lactones, preparation, 334 Hydroxylamines, preparation, 633 o-Hydroxylamino cyanides, preparation, 6Q7... 

A solution of 20 g. (0.12 mole) of o-aminobiphenyl in hydrochloric acid is diazotized in the usual manner [Org. Syntheses Coll. Vol. 1, 170 (1941)], and the solution of the diazonium salt is added to a solution of cuprous cyanide prepared from 35 g. of copper sulfate [Org. Syntheses Coll. Vol. 1, 514 (1941)]. When evolution of nitrogen ceases, the mixture is warmed for 30 minutes on a water bath and then made alkaline with sodium hydroxide. The mixture is steam-distilled, and the distillate is agitated with stannous chloride solution. SuflBcient sodium hydroxide is added to precipitate the tin, and the mixture is extracted with ether. The ethereal solution is dried and distilled to give 11.0 g. (50%) of o-cyanobiphenyl boiling at 174°/13 mm., m.p. 37°. 

Sodium copper cyanide A mixed cyanide prepared from NaCN with CuCN, used to convert vinyl bromides to vinyl cyanides. 

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