| 829 kg/m³|
| Colorless or pale yellow liquid|
2-Undecanone, also known as methyl nonyl ketone and IBI-246, is an oily organic liquid manufactured synthetically, but which can also be extracted from oil of rue. It is found naturally in bananas, cloves, ginger, guava, strawberries, wild-grown tomatoes, and the perennial Houttuynia cordata.
2-Undecanone is used in the perfumery and flavoring industries, but because of its strong odor it is primarily used as an insect repellent or animal repellent. Typically, 1–2% concentrations of 2-undecanone are found in dog and cat repellents in the form of a liquid, aerosol spray, or gel.
Research from North Carolina State University has shown that it may be useful as a mosquito repellent, as effective as, or even more effective than, DEET.
2-Undecanone is a ketone that is soluble in ethanol, benzene, chloroform, and acetone, but its large carbon chain renders it insoluble in water. Like most methyl ketones, 2-undecanone undergoes a haloform reaction when in the presence of a basic solution of hypochlorite. For example, the reaction between 2-undecanone and sodium hypochlorite yields sodium decanoate, chloroform, and sodium hydroxide.
+ 3 NaOCl → CH3
COONa + CHCl3
+ 2 NaOH