propil

Propil, often written propyl in chemical contexts, is an alkyl substituent with the formula C3H7 derived from propane by removal of one hydrogen atom. As a substituent, it is attached to a parent molecule at a carbon atom, forming countless propyl-substituted compounds such as propyl benzene or propyl esters.

There are two structural isomers of propil: n-propil (propane-1-yl) and isopropil (propane-2-yl). The n-propil group is a straight chain, while the isopropil group is branched. In IUPAC nomenclature, they are called propan-1-yl and propan-2-yl respectively.

Propil groups are nonpolar and hydrophobic, contributing three carbon atoms to a molecule. Their presence influences lipophilicity, volatility, and solubility of compounds, depending on the rest of the structure.

Propil groups can be installed into molecules through various organic transformations, including alkylation with propyl halides, reduction of propionates, or condensation reactions forming propyl esters and propyl ethers. They appear widely in pharmaceuticals, agrochemicals, flavors and fragrances, and as building blocks in organic synthesis.

Related terms include propanol derivatives such as propan-1-ol and propan-2-ol, which are not propyl groups themselves but contain propyl carbon skeletons. Safety and handling depend on the specific compound containing the propil group; many propyl-containing substances are flammable and may pose health hazards, requiring standard chemical hygiene practices.