4-Hydroxyphenylacetonitrile is a naturally occurring nitrile.
4-Hydroxyphenylacetonitrile occurs alongside 4-hydroxybenzylisothiocyanate as a degradation product of glucosinalbin, which is found in white mustard. The cabbage butterfly, which feeds on cruciferous plants containing glucosinalbin, among other things, can evade the toxicity of isothiocyanate by specifically breaking down glucosinalbin to 4-hydroxyphenylacetonitrile, which it can further metabolize. The horseradish tree contains niazirine, a glycoside of 4-hydroxyphenylacetonitrile.
The hydrogenation of 4-hydroxyphenylacetonitrile under palladium catalysis yields tyramine.