The Optimization of Synthesis Process of 4-Amino-3-nitrophenol

4-Amino-3-nitrophenol can be synthesized from p-aminophenol as raw material through acetylation,nitration and hydrolysis.The synthesis method was optimized by controlling of the dosage of acetic anhydride and nitric acid,and using ethanol as solvent.The optimum conditions include as following: a dosage ratio of n(p-aminophenol) ∶ n(acetic anhydride) ∶ n(fuming nitric acid) =1 ∶ 3.3 ∶ 1.2,acetylation for 2 h and nitration for 1.5 h;n(4-acetamido-3-nitrobenzoicphenol acetate) ∶ n(sodium hydroxide) ∶ n(ethanol) =1 ∶ 4 ∶ 15 in hydrolysis,and hydrolysis for 1h.Comparing with the conditions that mentioned in the literature[2],the consumption of nitric acid for nitration was reduced to 1/5,the hydrolysis time was reduced to 1 /4,and the total yield was increased from 58.2% to 69.4%.