Abstract 5-Nonylsalicylaldehyde was the important intermediates in the synthesis of 5-nonylsalicylaldoxime, which as copper extraction agent had many applications in industry. In this paper, 5-nonylsalicyaldehyde was synthesized from 4-nonylphenol, hexamethylenetetramine in acetic acid via Duff reaction. Compared to the other synthesis methods, the synthesis method of 5-nonylsalicyaddehyde used Duff reaction has much advantages, such as simple operation, short reaction period, single product and easy to be purified. The effects of reactant mole ratio, reaction temperature, reaction time on the reaction yield were studied. The optimum reaction conditions were as follows: n(4-nonylphenol):n(hexamethylenetetramine)=1:2 and the reaction mixture was dissolved in acetic acid and stirred at 90 ℃ for about 6 h. Under these conditions, the yield of 5-nonylsalicyaldehyde was 98.7% based on 4-nonylphenol with a purity of 92.0% (analyzed by HPLC). Structure of the product was elucidated by 1H-NMR analysis.
2014, Vol. 31 
