Cyanoacetylene

2-Propynenitrile, is the simplest cyanopolyyne. It has been detected by spectroscopic methods in interstellar clouds, in the coma of comet Hale–Bopp and in the atmosphere of Saturn''s moon Titan, where it sometimes forms expansive fog-like clouds.

Cyanoacetylene can be used for nucleophilic conjugate additions to (Z)-olefins; Diels-Alder reactions, and dipolar cycloadditions with nitrones and diazo compounds.

Cyanoacetylene is not commercially available, but can be prepared on a several gram scale by the dehydration of  propynamide (propiolamide) with Phosphorus(V) Oxide (eq 1). The reactants are well ground together under nitrogen, and  upon subjection of the resulting solid mixture to high temperature treatment, propynenitrile is collected as a distillate in a  receiver held at 5 °C.