Search for Interstellar Acrylonitrile, Pyrimidine, and Pyridine

We report the results of a negative search at 6 mm for acrylonitrile (expected as a hydrogenation product of cyanoacetylene) and the ring compounds pyrimidine, and pyridine. The estimated upper bound on the column density of acrylonitrile in Sgr B2 is a few percent that of cyanoacetylene. The implications of this for the effectiveness of hydrogenation reactions on the surfaces of grains in the molecular clouds are discussed. Subject headings: molecules, interstellar - nebulae - radio lines