The Feb 1 Astrophysical Journal (ApJ) (vol. 997 #2) contains:
Tribbett, P. D. Yarnall, Y. Y. Gerakines, P. A. et al. Radiation-driven Destruction of N-heterocycles in the Presence and Absence of Water Ice Art 291 ae22f0
Asteroids contain organics. That’s right, bodies floating in space contain organic chemicals. Such chemicals exist in space, condense onto grains of dust and ice, and get incorporated into bigger and bigger bodies. We then find them in meteorites, and the samples we collect from certain asteroids.
Of course, space is a hostile environment. While the UV light, cosmic rays, and hypervelocity impacts can stir chemicals into different chemicals, they can also destroy them completely. The action of water also includes radicals (protium and hydroxyl) that can lyse organic molecules. Tribbett et al. consider organics, in the wake of the OSIRIS-REx and Hayabusa2 missions. Both Ryugu and Bennu show the presence of water and organics, of various types and forms.