A Study on the Novel Technique for the Synthesis of 5-Nitrosalicylic Acid

Using 2-chloro-5-nitrobenzoic acid as a raw material, 5-nitrosalicylic acid was prepared by base-catalyzed hydrolysis and acidification. The effects of concentration of K2CO3/KOH,mass ratio of K2CO3/KOH and 2-chloro-5-nitrobenzoic acid, reaction temperature an time on the yield of 5-nitrosalicylic acid were investigated, and the optimal conditions were acquired, and the method of extraction and purification was discussed. Under the optimal reaction conditions, which mass ratio of K2CO3/KOH and 2-chloro-5-nitrobenzoic acid was 80:100,reaction temperature was in the range of 130~140℃ and reaction time was 15h, the experiment has been carried out ,and the yield of 5-nitrosalicylic acid is ≥95%, the melting point is in the range of 230~232 ℃,and the mass fraction of 5-nitrosalicylic acid potassium is ≥98.5%.