ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC/2Oc1c%28cccc1%5CC%3DC%5C2%29N3CCNCC3/file?format=sdf&get3d=True  -- O%3DC/2Oc1c%28cccc1%5CC%3DC%5C2%29N3CCNCC3 could not be loaded.