ACETOPHENONE or Phenyl Methyl Ketone is the simplest representative of the mixed aliphatic-aromatic ketones. It crystal lizes in colourless leaflets with a characteristic odour; it melts at 2o° C and boils at 202° C, is volatile in steam and has the com position, It occurs to a small extent in coal tar and, having feebly basic properties, is extracted from the heavy oil fractions (b.p. with sulphuric acid.
Acetophenone condenses with phenylhydrazine but does not combine with sodium hydrogen sulphite. It results from the dis tillation of a mixture of dry calcium acetate and benzoate but is best prepared by condensing benzene and acetyl chloride with aluminium or ferric chloride in carbon disulphide. It has anaes thetic and soporific properties and under the name of hypnone has been used as a drug to induce sleep. With hydroxylamine it con denses to acetophenoneoxime, :NOH, which, under the influence of phosphorus pentachloride in ether is converted into the isomeric acetanilide, this transformation being an example of the so-called Beckmann change which occurs with ketone oximes in general.
p-Aminoacetophenone also has anaesthetic properties, whereas the condensation product of acetophenone and phenetidine is an antipyretic substance. On adding sodium to acetophenone dis solved in ethyl acetate the sodium derivative of benzoylacetone is produced from which benzoylacetone, is obtained by acidification, this condensation being a typical example of the Claisen reaction.