Methane sulphonic acid (MsOH) 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 (or methanesulfonates, as in ethyl methanesulfonate). It is hygroscopic in its concentrated form
M 1815 (OTTO) Methane sulphonic acid, 98% Cas 75-75-2 - used as an acid catalyst in organic reactions because it is a non-volatile, strong acid that is soluble in organic solvents.