Bromomethyl methyl ether (MOM-Br) is primarily used as a reagent in organic synthesis for introducing the methoxymethyl (MOM) protecting group, particularly to alcohols, amines, and carboxylic acids. This protection strategy is essential in multi-step syntheses to temporarily mask reactive functional groups. It is especially valuable in pharmaceutical manufacturing, enabling the selective modification of complex drug molecules without interference from unprotected sites. Additionally, it serves as an alkylating agent in the preparation of ethers and other fine chemicals, and finds applications in the synthesis of agrochemicals and natural products. Due to its high reactivity, lachrymatory properties, and potential carcinogenicity, it requires careful handling under controlled laboratory conditions.