monobromoacetic

Monobromoacetic acid, also known as 2-bromoacetic acid or α-bromoacetic acid, is an organobromine carboxylic acid. Its formula is C2H3BrO2, and its structure is Br–CH2–COOH, a bromomethyl group adjacent to a carboxyl group. It typically exists as a colorless, hygroscopic liquid or solid at room temperature and is miscible with water and many organic solvents.

Preparation and related chemistry

Monobromoacetic acid is commonly prepared by selective bromination of acetic acid, often using bromine under suitable catalytic conditions to yield the mono-brominated product. It can also be produced from brominated acetyl derivatives or via transformations of related haloacetyl compounds. The molecule features an activated methylene group next to the carbonyl, making the α-carbon relatively acidic and prone to deprotonation. The bromomethyl carbon is a good leaving group, enabling nucleophilic substitutions to form a wide range of derivatives.

Reactions and uses

As a versatile haloacetic acid, monobromoacetic acid participates in typical haloacetic acid chemistry. Deprotonation at the α-position forms enolates that can engage in various nucleophilic additions and substitutions. The bromine atom readily undergoes SN2 reactions with amines, thiols, and other nucleophiles, allowing the preparation of substituted acetic acids, esters, and amides after appropriate workups. It can also be used to introduce the bromomethyl group into target molecules, serving as a building block in organic synthesis.

Safety

Monobromoacetic acid is corrosive and can cause burns to skin and eyes, as well as respiratory irritation if vapors are inhaled. It reacts with bases to form carboxylate salts and hydrogen bromide. Proper protective equipment and handling in a well-ventilated area are essential.