The IUPAC name of this organic molecule is butanenitrile. Under standard laboratory conditions it is a colorless liquid that is miscible with most polar organic solvents.
Propyl cyanide is among the largest organic molecules unambiguously detected by radio astronomers in the interstellar medium (Belloche et al. 2009). These authors suggest that it may be produced by surface reactions on interstellar dust grains, perhaps by sequential addition of CH2 or CH3 radicals to known interstellar species such as CN and CH2CN. It is the third member of the series that includes methyl cyanide (CH3CN) and ethyl cyanide (CH3CH2CN).