ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28Oc1cc%28nn1C%28C%29C%29C%29N%28C%29C/file?format=sdf&get3d=True  -- O%3DC%28Oc1cc%28nn1C%28C%29C%29C%29N%28C%29C could not be loaded.