The IUPAC name of this product is 5-amino-2-methylbenzenesulfonic acid. With the CAS registry number 118-88-7, it is also named as p-Toluidine-o-sulfonic acid; 3-Amino-6-methylbenzenesulfonic acid. The product is an ntermediates of dyes and pigments. It can be used as additives and blue regulator in the synthetic pigment Red 57 #.

The other characteristics of this product can be summarized as: (1)ACD/LogP: -0.60; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -3.92; (4)ACD/LogD (pH 7.4): -4.09; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 4; (10)#H bond donors: 3; (11)#Freely Rotating Bonds: 2; (12)Index of Refraction: 1.61; (13)Molar Refractivity: 45.34 cm³; (14)Molar Volume: 130.7 cm³; (15)Polarizability: 17.97×10^-24 cm³; (16)Surface Tension: 61.7 dyne/cm; (17)Rotatable Bond Count: 1; (18)Exact Mass: 187.030314; (19)MonoIsotopic Mass: 187.030314; (20)Topological Polar Surface Area: 88.8; (21)Heavy Atom Count: 12; (22)Complexity: 244.

The 5-Amino-2-methylbenzenesulfonic acid can be obtained by 4-methyl-aniline. This reaction needs reagent sulfuric acid monohydrate and solvent 1,2-dichloro-benzene at temperature of 175-180 °C. The reaction time is 3-5 hours. The yield is 94.6%.

This chemical also can be used in the preparation of 5-dimethylamino-2-methyl-benzenesulfonic acid. This reaction needs reagent H₂, catalytic agent Pd/C and solvent methanol. The yield is 100%.

When you are using this chemical, please be cautious about it as the following. The 5-Amino-2-methylbenzenesulfonic acid is harmful by inhalation, in contact with skin and if swallowed. It can cause burns. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. If you want to contact this product, you must wear suitable protective clothing, gloves and eye/face protection.

People can use the following data to convert to the molecule structure. 
1.SMILES: O=S(=O)(O)c1c(ccc(N)c1)C; 
2.InChI: InChI=1/C7H9NO3S/c1-5-2-3-6(8)4-7(5)12(9,10)11/h2-4H,8H2,1H3,(H,9,10,11).