The large family of detected interstellar cyanide compounds was expanded again in 2015 with the disovery of n-propyl cyanide (n-C₃N₇CN) by Belloche et al. The anti conformer of the compound was detected toward Sgr B2(N) on the basis of 50 unblended transitions, with no missing lines; the gauche conformer was not detected. Likewise, neither form of n-propyl cyanide was detected toward the adjacent source Sgr B2(M). The observed lines were part of an extensive survey made with the IRAM 30m telescope. Subsequent experimental work by Müller et al. characterized transitions of vibrationally excited n-propyl cyanide and led to its detection in Sgr B2(N).

n-Propyl cyanide or butyronitrile or n-butanenitrile is used as a solvent. Iso-propyl cyanide has also been detected in space.