ERROR opening https://cactus.nci.nih.gov/chemical/structure/COc1cccc%28c1%29c3nccc2NC%28%3DO%29%5CC%28%3DC/c23%29c4nc%28C%29on4/file?format=sdf&get3d=True  -- COc1cccc%28c1%29c3nccc2NC%28%3DO%29%5CC%28%3DC/c23%29c4nc%28C%29on4 could not be loaded.