Aliphatic and aromatic primary amines when warmed with chloroform and an alcoholic solution of KOH , form isocyanide or carbylamine. ethyl amine C2H5NH2+ chloroform CHCl3+3KOH (alc.) Warm ethyl isocyanide C2H5NC+3KCl+3H2O
Carbylamine reaction is a characteristic reaction of primary amines and can be used to distinguish primary amines from secondary and tertiary amines.