4-Acetoxybenzoyl chloride and 4-hydroxybenzaldehyde were used to prepare (4-formyl)phenyl 4-acetoxybenzoate, m.p. 98-100° C., in 45% yield. 18 g (0.063 mol) of this aldehyde were dissolved in 180 ml of glacial acetic acid, 9.5 g of potassium manganate and 180 ml of methyl ethyl ketone were added, and the mixture was heated to 50° C. with stirring. After 8 hours of stirring it was acidified with hydrochloric acid, 250 ml of ethyl acetate were added, and the phases were worked up. The concentrated ethyl acetate solution gave 16.8 g (89%) of 4-(4-acetoxybenzoyloxy)benzoic acid, C6H12O6 (300.3). The acid chloride was obtained in 95% yield from this acid by customary reaction with thionyl chloride.
