Magnesium bromide (MgBr2) is a chemical compound of magnesium and bromine that is white and deliquescent. It is often used as a mild sedative and as an anticonvulsant for treatment of nervous disorders .It is water soluble and somewhat soluble in alcohol.

Magnesium bromide can be synthesized by reacting hydrobromic acid with magnesium oxide and crystallizing the product. It can also be made by reacting magnesium carbonate and hydrobromic acid, and collecting the solid left after evaporation.

An alternative route is adding magnesium to a solution of liquid ammonia and sodium bromide, then evaporating the solvent off and collecting the precipitate

Magnesium bromide is used at a catalyst for many actions,typically as a  solvent or used as a Grignard reagent.