Butyl cyanide n-valeronitrile

Into a 1500 ml. round-bottomed flask place 97 5 g. of finely-powdered sodium cyanide (1), 125 ml. of water, and a few chips of porous porcelain. Attach a reflux condenser and warm on a water bath until all the sodium cyanide dissolves. Introduce a solution of 250 g. (196 ml.) of -butyl bromide (Sections 111,35 and 111,37) in 290 ml. of pure methyl alcohol, and reflux gently on a water bath for 28-30 hours. Cool to room temperature and remove the sodium bromide which has separated by filtration through a sintered glass funnel at the pump wash the crystals with about 100 ml. of methyl alcohol. Transfer the filtrate and washings to From n-caproamide by SOClj method. 

The tso-nitrile may be removed by the following procedure. Shake the crude (undistiUed) 7i-butyl cyanide twice with about half its volume of concentrated hydrochloric acid and separate carefully after each washing then wash successively with water, saturated sodium bicarbonate solution and water. Dry with anhydrous calcium chloride or anhydrous calcium sulphate, and distil. Ck)llect the pure n-butyl cyanide at 139-141°. If a fraction of low boiling point is obtained (because of incomplete drying), dry it again with anhydrous calcium sulphate and redistil. The yield is 95 g. 

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For practice, the student should carry out both alkaUne (compare Section 111,83) and acid hydrolysis of acetonitrile, n-valeronitrile (n-butyl cyanide) and n-capronitrile (n-amyl cyanide). 

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