Methanesulfonic acid is a colorless liquid with the chemical formula CH₃SO₃H. It is the simplest of the alkylsulfonic acids. Salts and esters of methanesulfonic acid are known as mesylates. It is also called  Methanesulphonic acid, methanesulphonic-acid-, Sulfomethane, CCRIS 2783, HSDB 5004.  Methanesulfonic acid is used as an acid catalyst in organic reactions because it is non-volatile, strong acid that is soluble in organic solvents.Methanesulfonic acid toxic is people .It shoule be Keeped  locked up and out of the reach of children.when you use it, you should  wear suitable protective clothing. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. In case of accident or if you feel unwell, seek medical advice immediately (show label where possible).

Physical properties about Methanesulfonic acid are:
(1)ACD/LogP: -2.087; (2)ACD/LogD (pH 5.5): -5.39; (3)ACD/LogD (pH 7.4): -5.58; (4)ACD/BCF (pH 5.5): 1.00; (5)ACD/BCF (pH 7.4): 1.00; (6)ACD/KOC (pH 5.5): 1.00 ; (7)ACD/KOC (pH 7.4): 1.00; (8)#H bond acceptors: 3 ; (9)#H bond donors: 1; (10)Index of Refraction: 1.448; (11)Molar Refractivity: 17.019 cm³; (12)Molar Volume: 63.581 cm³; (13)Polarizability: 6.747 10-24cm³; (14)Surface Tension: 53.3790016174316 dyne/cm; (15)Density: 1.512 g/cm³

Preparation of Methanesulfonic acid:
A process for the preparation of methanesulfonic acid comprising reacting sulfite ions within an aqueous system with dimethyl sulfate at an elevated temperature and, subsequently, adding a strong acid, wherein the molar ratio of sulfite ions to dimethyl sulfate is 1.5 to 2.5:1, and the reaction is maintained at said elevated temperature for at least 2 h.

Uses of Methanesulfonic acid:
Methanesulfonic acid may be considered an intermediate compound between sulfuric acid (H₂SO₄), and methylsulfonylmethane ((CH₃)2SO₂), effectively replacing an -OH group with a -CH₃ group at each step. This pattern can extend no further in either direction without breaking down the -SO₂ group. Methanesulfonic acid can be used in the generation of BH₃. By reacting methanesulfonic acid with NaBH₄ in an aprotic solvent such as THF or DMS, the complex of BH₃ and the solvent is formed.

You can still convert the following datas into molecular structure:
(1)InChI=1S/CH4O3S/c1-5(2,3)4/h1H3,(H,2,3,4);
(2)InChIKey=AFVFQIVMOAPDHO-UHFFFAOYSA-N;
(3)SmilesS(=O)(=O)(C)O;

The toxicity data of Methanesulfonic acid is as follows: