Ethylmagnesium bromide is widely used in organic synthesis as a Grignard reagent. It reacts with carbonyl compounds like aldehydes, ketones, and esters to form alcohols, making it valuable for constructing carbon-carbon bonds. This reagent is particularly useful in the synthesis of complex organic molecules, including pharmaceuticals and fine chemicals. It also plays a role in the preparation of tertiary alcohols and in the alkylation of various substrates. Due to its high reactivity, it is often employed in anhydrous conditions to avoid decomposition.