Phenyl benzoate, C 6 H 5.
An alternative method consists in converting it into ethyl benzoate by shaking with benzoyl chloride and caustic soda.
It is made commercially by boiling benzotrichloride (obtained from toluene) with milk of lime, the calcium benzoate so obtained being then decomposed by hydrochloric acid 2C 6 H 5 CC1 3 +4Ca(OH) 2 = (C6H6000)2Ca-1-3CaC12+4H20.
Benzoic anhydride, (C 6 H 5 C0) 2 0, is prepared by the action of benzoyl chloride on sodium benzoate, or by heating benzoyl chloride with anhydrous oxalic acid (R.
Ethyl benzoate, C 6 H S 000C 2 H 5, is best prepared by boiling benzoic acid and alcohol with a small quantity of sulphuric acid for some hours (E.
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.
Heated with an excess of lime it gives benzene; calcium benzoate results when calcium phthalate is heated with one molecule of lime to 330°-350°.
(Ethyl benzoate may be employed instead of benzoyl glycollic acid for this reaction.) This compound gave a nitroso compound with nitrous acid, which changed spontaneously into benzoylazoimide by loss of water: C 6 H 5 CO NH.
The resulting benzoylazoimide is easily hydrolysed by boiling with alcoholic solutions of caustic alkalis, a benzoate of the alkali metal and an alkali salt of the new acid being obtained; the latter is precipitated in crystalline condition on standing.
It may also be prepared by oxidizing benzyl alcohol with concentrated nitric acid; by distilling a mixture of calcium benzoate and calcium formate; by the condensation of chlor-oxalic ester with benzene in the presence of aluminium chloride, the ester of the ketonic acid formed being then hydrolysed and the resulting acid distilled: C 6 H 6 +Cl CO Cooc 2 H 5 = C,H5co COOC2H5d-HC1, C 6 H 5 CO 000H =C6H5CHO+C02; by the action of anhydrous hydrocyanic acid and hydrochloric acid on benzene, an aldime being formed as an intermediate product: C 6 H 6 +HCN+HC1= C6H5CH :NH HC1, Benzaldine hydrochloride C 6 H 5 CH: NH HC1+H 2 O =NH4C1+C6H5CHO; and by the action of chromium oxychloride on toluene dissolved in carbon bisulphide (A.