C2H5MgCl

Ethylmagnesium chloride, with the chemical formula C2H5MgCl, is an organomagnesium compound classified as a Grignard reagent. It serves as a versatile ethyl nucleophile and strong base in organic synthesis and is typically used to build carbon–carbon bonds and-derived alcohols.

Preparation and structure

Ethylmagnesium chloride is prepared by reacting an ethyl halide (ethyl chloride or bromide) with magnesium metal in an anhydrous, ether-containing solvent such as diethyl ether or tetrahydrofuran (THF) under inert atmosphere. In solution, Grignard reagents like C2H5MgCl exist as solvated, sometimes aggregated species, with the magnesium center coordinated by the ether solvent.

Reactivity and applications

As with other Grignard reagents, C2H5MgCl is highly reactive with water and oxygen, and it reacts readily with atmospheric moisture, necessitating strictly dry conditions. It also reacts with carbon dioxide to yield propionic acid after acidic workup. In carbonyl chemistry, it adds to aldehydes and ketones to form alcohols after hydrolysis: reaction with formaldehyde gives primary alcohols, with other aldehydes gives secondary alcohols, and with ketones yields tertiary alcohols. It can also open epoxides to extend the carbon framework. In practice, ethylmagnesium chloride is used to introduce an ethyl group in synthesis, or as a base to deprotonate certain substrates under controlled conditions.

Handling and safety

The reagent is moisture- and air-sensitive and is typically handled under inert conditions in dry solvents. Ether solvents are flammable and can form peroxides, requiring proper storage and precautions. Proper PPE, ventilation, and preparation for quenching with appropriate acids or water are essential to safety.

See also

Grignard reagents; organomagnesium chemistry; carbon–carbon bond formation.