Methylmagnesium bromide is a chemical compound with the chemical formula CH3BrMg and a molecular weight of 119.24352 g/mol. It is a clear brown solution when properly stored or a colorless cloudy solution in diethyl ether.
Methylmagnesium bromide is formed when magnesium reacts with bromomethane, as given by the equation Mg + CH3Br --> CH3BrMg. CH3BrMg is key in the manufacture of Naproxen, a drug that is used in the treatment of rheumatoid arthritis. Methylmagnesium bromide is a highly flammable solution that reacts with water and moisture in the air to form methane gas. If the heat of reaction with water is high enough, the methane gas can explode, causing fire.