3methoxy

3-methoxy refers to a methoxy substituent attached at the third position of a parent molecule. The methoxy group (-O-CH3) is an alkoxy substituent commonly introduced to aromatic systems by O-alkylation or methoxylation. The locant 3- indicates the position of the substituent on a ring or chain relative to other reference groups. Examples include 3-methoxyphenol, 3-methoxybenzoic acid, and 3-methoxytoluene.

Chemically, the methoxy group is electron-donating by resonance, increasing electron density on the ring and generally activating it toward electrophilic substitution at ortho and para positions relative to the methoxy. It is polar and can influence properties such as solubility and lipophilicity. The group also participates in hydrogen bonding as a weak donor or acceptor in some contexts.

3-methoxy substituents occur in natural products, including certain flavonoids and phenylpropanoids, and in synthetic compounds used in flavors, fragrances, pharmaceuticals, and agrochemicals. In nomenclature, specifying the 3-position helps define isomeric identity, which can affect biological activity and physical properties.

As with many organics, handling methoxy-containing compounds should follow standard safety guidelines, with attention to the specific hazards of individual substances, including flammability and vapor risks.