An improved synthetic process for 3-benzyloxy-4-n-butylaniline hydrochloride the key intermediate of nequinate which is an anticoccidal drug to parasites of Eimeria,was described.The process was started with 3-aminophenol,via acylation,Fries rearrangement,benzylation,hydrolysis,and Huang-Minlon reduction,to give the title compound.The optimal reaction conditions and molar yield were as follows:acylation,130—140℃ for 3 h;Fries rearrangement,140℃ for 5 h,77.9%(based on 3-aminophenol);benzylation,70℃ for 2 h and 80℃ for 4 h,81.3%;hydrolysis and Huang-Minlon reduction,reflux for 90 min,78.2%.The structures of the main compounds were confirmed by 1H NMR.The process is much of industrial value because of high yields,cheap and available materials,moderate reaction conditions and convenient operations.
