The IUPAC name of Sulfanilic acid is 4-aminobenzenesulfonic acid. With the CAS registry number 121-57-3, it is also named as Aniline-4-sulfonic acid; Benzenesulfonic acid, 4-amino-. The product's categories are intermediates of dyes and pigments, inorganic & organic chemicals and organics. It is greyish-white crystals or powder which is stable and incompatible with strong oxidizing agents. It will produce toxic nitrogen oxide and sulfur oxide gases when buring. So the storage environment should be ventilate, low-temperature and dry. Keep Sulfanilic acid separate from raw materials of food.

The other characteristics of Sulfanilic acid can be summarized as: 
(1)ACD/LogP:  -1.568; (2)# of Rule of 5 Violations:  0; (3)ACD/LogD (pH 5.5):  -5.05; (4)ACD/LogD (pH 7.4):  -5.07; (5)ACD/BCF (pH 5.5):  1.00; (6)ACD/BCF (pH 7.4):  1.00; (7)ACD/KOC (pH 5.5):  1.00; (8)ACD/KOC (pH 7.4):  1.00; (9)#H bond acceptors:  4; (10)#H bond donors:  3; (11)#Freely Rotating Bonds:  2; (12)Index of Refraction:  1.63; (13)Molar Refractivity:  40.72 cm³; (14)Molar Volume:  114.49 cm³; (15)Surface Tension:  67.5469970703125 dyne/cm; (16)Density:  1.513 g/cm³.

Preparation of Sulfanilic acid:
It can be obtained by 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 87.2%.


Uses of Sulfanilic acid:
 It is used to make dyes and sulpha drugs. It is also used in the manufacture pesticides which can cure wheat rust disease. In addition, it can be used in many organic synthesis. For example: It reacts with 6-chloro-pyrimidine-2,4-diamine to get 2,4-diamino-6-p-sulphoanilinopyrimidine.  This reaction needs reagent cc HCl and solvent ethanol by heating. The reaction time is 4.0 hours. The yield is 85%.


When you are using Sulfanilic acid, please be cautious about it as the following:
It may cause burns and is irritating to eyes and skin. So people should avoid contact with skin. 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. In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)

People can use the following data to convert to the molecule structure.
(1)SMILES:O=S(=O)(O)c1ccc(N)cc1;
(2)Std. InChI:InChI=1S/C6H7NO3S/c7-5-1-3-6(4-2-5)11(8,9)10/h1-4H,7H2,(H,8,9,10);
(3)Std. InChIKey:HVBSAKJJOYLTQU-UHFFFAOYSA-N.

The following is the toxicity data of Sulfanilic acid: