2',4'-dihydroxybutyrophenone

107-92-6

108-46-3

4390-92-5

To a 2.0 L four-neck flask was added 165.0 g of resorcinol (1.5 mol) followed by 1.0 L of toluene as a solvent. Under stirring conditions, 158.6 g (1.8 mol) of n-butyric acid was slowly added, followed by 245.3 g (1.8 mol) of zinc chloride as a catalyst. The reaction mixture was heated to reflux while the water generated during the reaction was separated by means of a water separator. The reaction process was monitored by gas chromatography (GC) until the reaction was completed. Upon completion of the reaction, the zinc catalyst was first removed and then the organic phase was washed sequentially with water and saturated sodium bicarbonate solution for purification. Finally, 241.5 g of 4-butyrylresorcinol was obtained by concentrating the organic phase in 89.3% yield.