An alternative method consists in converting it into ethyl benzoate by shaking with benzoyl chloride and caustic soda.
They are readily decomposed by mineral acids with the production of benzoic acid, and on addition of ferric chloride to their neutral solutions give a reddish-brown precipitate of ferric benzoate.
Benzamide, C 6 H 5 CONH 2, is prepared by the action of benzoyl chloride on ammonia or ammonium carbonate, or from ethyl benzoate and ammonia.
Benzoic acid itself, ammonium benzoate and sodium benzoate are all administered internally in doses of from five to thirty grains.
It may be prepared by distilling calcium benzoate; by condensing benzene with benzoyl chloride in the presence of anhydrous aluminium chloride; by the action of mercury diphenyl on benzoyl chloride, or by oxidizing diphenylmethane with chromic acid.