Chlorination of propiophenone in alkaline aqueous solution leads to formation of α- hydroxypropiophenone as the first detectable intermediate; this undergoes slower oxidation to aromatic acids without any accumulation of further intermediates. From the rates of the initial chlorination we have been able to determine the p K a value as 17.56±0.51. Key words: propiophenone, chlorination, hydrolysis, rearrangement, p K a.
