Aliphatic amines can be prepared by gently warming halogenoalkanes with excess ammonia in an ethanol solvent. Ammonia acts as a nucleophile and an amine group is substituted for the halogen atom. However, the product is a primary amine and can also act as a nucleophile. This further reacts with the halogenoalkane to form a secondary amine, which also reacts and forms a tertiary amine. Further substitution is minimised by adding an excess of ammonia.A purer product can be obtained by reacting halogenoalkanes with potassium cyanide in ethanol to form a nitrile and then hydrogenating with hydrogen gas and a nickel catalyst.Phenylamine can be prepared from the reduction of nitrobenzene by heating it under reflux with tin (Sn) and concentrated hydrochloric acid.