2Hydroxyethyl

2hydroxyethyl is a two-carbon hydroxyalkyl substituent, typically represented as the fragment -CH2-CH2-OH, and it attaches to a parent molecule through the first carbon. The terminal hydroxyl group makes this substituent polar and reactive, enabling further modification by esterification, etherification, or other transformations. It is a common building block in organic synthesis and polymer chemistry.

Preparation and reactivity: The 2hydroxyethyl fragment is usually introduced by opening ethylene oxide with a nucleophile (such as an alkoxide, amine, or alcohol) to form 2-hydroxyethyl ethers, or by substitution of a suitable leaving group with hydroxide. This moiety also appears in various monomers and derivatives, including 2-hydroxyethyl methacrylate (HEMA) and related polymers, which illustrate its role as a functional handle for polymer design.

Applications: In polymers and materials science, the 2hydroxyethyl group imparts hydrophilicity and provides reactive sites for crosslinking, grafting, or further functionalization. It is found in hydrogel formulations, contact-lens polymers, and cellulose derivatives such as 2-hydroxyethyl cellulose. Simple 2hydroxyethyl esters (for example, 2-hydroxyethyl acetate) serve as solvents, plasticizers, or industrial intermediates.

Safety and handling: The safety profile depends on the specific compound containing the 2hydroxyethyl group. While the moiety itself is a common chemical feature, some derivatives can be irritants or harmful. Synthesis often involves reactive intermediates such as ethylene oxide, which requires appropriate protective measures due to its toxicity and carcinogenic potential.

See also: Ethylene oxide; Ethylene glycol; 2-hydroxyethyl methacrylate; 2-hydroxyethyl cellulose.