This compound is readily oxidized to benzoic acid, C 6 H 5 000H, the aromatic residue being unattacked; nitric and sulphuric acids produce nitro-toluenes, C6H4 CH3 N02j and toluene sulphonic acids, C 6 H 4 CH 3 SO 3 H; chlorination may result in the formation of derivatives substituted either in the aromatic nucleus or in the side chain; the former substitution occurs most readily, chlor-toluenes, C 6 H 4 CH 3 Cl, being formed, while the latter, which needs an elevation in temperature or other auxiliary, yields benzyl chloride, C 6 H 5 CH 2 C1, and benzal chloride, C 6 11 5 CHC1 2.
Those substituted in the benzene nucleus are obtained by condensing two molecules of a substituted benzyl and benzal chlorides.
It can be prepared by the reduction of phenyl propiolic acid with zinc and acetic acid, by heating benzal malonic acid, by the condensation of ethyl acetate with benzaldehyde in the presence of sodium ethylate or by the so-called "Perkin reaction"; the latter being the method commonly employed.
OH +C 6 H 5 C HO, or, by conversion into benzal chloride, which is heated with milk of lime under pressure: C 6 H 5 CHC1 2 +CaO = CaC12+C6H5CHO.
Jacobsen has also obtained benzaldehyde by heating benzal chloride with glacial acetic acid: C 6 H 5 CHC1 2 +CH 3 000H =CH30001 +HC1+C6H5CHO.