The chemical dynamics to cyanoacetylene, HCCCN(X (1)Sigma(+)), formation via the neutral-neutral reaction of cyanogen, CN(X (2)Sigma(+)), with acetylene, C2H2(X (1)Sigma(g)(+)), is investigated in a crossed molecular beams experiment at a collision energy of 21.1 kJ mol(-1). The laboratory angular distribution and time-of-flight spectra of the HCCCN product are recorded at m/e=51 and 50. Forward-convolution fitting of our data reveals that the reaction dynamics are governed by an initial attack of the CN radical to the pi electron density of the acetylene molecule to form a HCCHCN collision complex on the (2)A' surface. The four heavy atoms are rotating in plane almost perpendicular to the total angular momentum vector J around the C axis of the complex which undergoes C-H bond rupture through a tight transition state to HCCCN and H. The H atom is emitted almost perpendicular to the HCCCN axis to yield a nearly "sideways" peaking of T(theta). The explicit identification of the cyanoacetylene reaction product represents a solid background for the title reaction to be included with more confidence in reaction networks modeling the chemistry in dark, molecular clouds, outflow of dying carbon stars, hot molecular cores, as well as the atmosphere of hydrocarbon rich planets and satellites such as the Saturnian moon Titan.