Sodium methanethiolate

Sodium methanethiolate or sodium thiomethoxide is an organosulfur compound with the formula CH₃SNa. It is the sodium salt of the conjugate base of methanethiol. This compound is commercially available as a white solid that is soluble in polar organic solvents. Sodium methanethiolate is a reagent in organic synthesis and a byproduct of some industrial processes. Hydrolysis of sodium methanethiolate, e.g. in humid air, produces methanethiol, which has a low odor threshold and a noxious "rotten egg" smell.

Preparation

Sodium methanethiolate can be produced by treating a solution of methanethiol in an etherial solvent with sodium hydride:
It is also prepared and used in situ by treatment of a solution of methanethiol with strong base such as sodium hydroxide.

Sodium methanethiolate is a source of methanethiolate, a powerful nucleophile. It is used to cleave methoxy-aryl ethers:
It converts alkyl halides to methyl thioethers:
Oxidation of sodium methanethiolate gives dimethyldisulfide: