The 5-nitrosalicylic acid is synthesized by nitration(generates the intermediate 2-Chloro-5-nitrobenzoic acid, http://www.guidechem.com/cas-251/2516-96-3.html) and hydrolysis(generates the target product) of o-chlorobenzoic acid. The influences of the nitration of temperature, proportion of mixed acid and of the hydrolysis of temperature, reaction time were investigated. The yield of nitration was 95.7% with a mixed acid of nitric acid : sulfuric acid = 9 : 1, in the course of 0 ? and 8h, and the yield of hydrolysis was 98.3% in the course of 140 ? and 16 h. The final product (HPLC?99.8%) was obtained after recrystallizing by the proper ethanol solution.
To prepare 5-nitrosalicylic acid, you need to have organic solvents or reagents and water. Dissolve potassium hydroxide pellets in the water and heat the mixture for 3-4 hours. Then, filter the mixture under nitrogen after it has fully heated and cooled and so as to be left with the acid. Read more at http://www.mdpi.org/molbank/m0260.htm.