The IUPAC name of Methylthioninium chloride is [7-(dimethylamino)phenothiazin-3-ylidene]-dimethylazanium chloride. With the CAS registry number 61-73-4, it is also named as 3,7-Bis(dimethylamino)phenothiazin-5-ium chloride; Methylene blue. The product's categories are analytical chemistry; ion association. It is green fine crystalline powder which is soluble in water and slightly soluble in ethanol. When burning it can produce toxic oxides fumes of nitrogen, chloride and sulfur, so the storage environment should be ventilate, low-temperature and dry.

The other characteristics of this product can be summarized as: (1)#H bond acceptors: 3; (2)#H bond donors: 0; (3)#Freely Rotating Bonds: 1; (4)Rotatable Bond Count: 1; (5)Exact Mass: 319.090996; (6)MonoIsotopic Mass: 319.090996; (7)Topological Polar Surface Area: 43.9; (8)Heavy Atom Count: 21; (9)Covalently-Bonded Unit Count: 2.

Preparation of Methylthioninium chloride: Using N, N-dimethyl aniline as the main raw material. Firstly, we get amino dimethyl aniline by nitrosation and reduction. Secondly, it is oxidized by Na₂Cr₂O₇.Na₂S₂O₃, and vulcanization and condensation to obtain thiazide. And finally, using ZnCl₂ to salt, we can get the product by filtration and drying.

Uses of Methylthioninium chloride: It is not only used to dye cotton, acrylic, hemp, silk, but also used to color paper and wood. And it is also used in the manufacture of ink and color lakes. In addition, it is used in Biological stain and redox indicator.

When you are using this chemical, please be cautious about it as the following:
It is flammable and harmful by inhalation, in contact with skin and if swallowed. Especially, it is risk of serious damage to the eyes. 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. 

People can use the following data to convert to the molecule structure.
1. SMILES: [Cl-].N=1c3c(SC=2C=1\C=C/C(=[N+](/C)C)/C=2)cc(cc3)N(C)C;
2. InChI: InChI=1/C16H18N3S.ClH/c1-18(2)11-5-7-13-15(9-11)20-16-10-12(19(3)4)6-8-14(16)17-13;/h5-10H,1-4H3;1H/q+1;/p-1.

The following are the toxicity data which has been tested.