of ammonium carboxylates with P O CH - COONH P O CH - CN + 2H O Ammonium acetate Ethanenitrile This method suitable for large scale preparation of alkyl cyanides. . From Grignard reagent Methyl magnesium bromide on treatment with cyanogen chloride (Cl - CN) forms ethanenitrile. CH - MgBr + Cl CN CH - CN + Mg Br Cl methyl magnesium bromide ethanenitrile .
. Properties Of Cyanides Physical Properties The lower members (up to C ) are colourless liquids with a strong characteristic sweet smell. The higher members are crystalline solids, They are moderately soluble in water but freely souble in organic solvents. They are poisonous.
They have higher boiling points than analogous acetylenes due to their high dipole moments. XII U13-Organic Nitrogen XII U13-Organic Nitrogen - - - - . . Chemical properties .
Hydrolysis On boiling with alkali (or) a dilute mineral acid, the cyanides are hydrolysed to give carboxylic acids. For example CH - CN + H O H O / OH - Partial hydrolysis CH - C - NH 2H O / H+ Complete hydrolysis CH - C - OH Acetamide Acetic acid Ethanenitrile . Reduction On reduction with LiAlH (or) Ni / H , alkyl cyanides yields primary amines. CH - CN + 2H Ni CH - CH - NH Ethanenitrile Ethanamine .
Condensation reaction a) Thorpe nitrile condensation Self condensation of two molecules of alkyl nitrile (containing a –H atom) in the presence of sodium to form iminonitrile. CH CH - C CH - CN Na Ether CH CH - C - CH -CN NH .. Propanenitrile - imino - - methyl pentanenitrile N + b) The nitriles containing α - hydrogen also undergo condensation with esters in the presence of sodamide in ether to form ketonitriles. This reaction is known as “ Levine and Hauser” acetylation This reaction involves replacement of ethoxy (OC H ) group by methylnitrile