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benzal
[ ben-zal ]
noun
- the benzal group.
Example Sentences
By heating benzal chloride with dry sodium acetate there is formed an acid known as cinnamic acid, a fragrant compound which derives its name from cinnamon, because the acid was prepared by the oxidation of oil of cinnamon by Dumas and Peligot in 1834.
The first of these is benzyl chloride, the second benzal chloride, and the third benzotrichloride or phenyl chloroform.
It was but a step from the laboratory into the factory in this case, and at the present time the aldehyde is made on a large scale by chlorinating boiling toluene beyond the stage of benzyl chloride, and heating the mixture of benzal chloride and benzotrichloride with lime and water under pressure.
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.
This compound is readily oxidized to benzoic acid, C6H5�COOH, the aromatic residue being unattacked; nitric and sulphuric acids produce nitro-toluenes, C6H4�CH3�NO2, and toluene sulphonic acids, C6H4�CH3�SO3H; 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, C6H4�CH3�Cl, being formed, while the latter, which needs an elevation in temperature or other auxiliary, yields benzyl chloride, C6H5�CH2Cl, and benzal chloride, C6H5�CHCl2.
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