ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28N%3DC%28N%29O1%29C1C2%3DCC%3DC%28C%29C%3DC2/file?format=sdf&get3d=True  -- CC%28N%3DC%28N%29O1%29C1C2%3DCC%3DC%28C%29C%3DC2 could not be loaded.