Mesalazine EP Impurity N Catalogue No. - VL98016 CAS No. - 96-97-9 Molecular Formula - C₇H₅NO₅ Molecular Weight - 183.12 IUPAC Name - 5-Nitrosalicylic Acid; 2-Hydroxy-5-nitrobenzoic Acid; 5-Nitro-2-hydroxybenzoic Acid;