ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1C2CNCC1C3%3DCC4%3DNC%3DCN%3DC4C%3DC23/file?format=sdf&get3d=True  -- C1C2CNCC1C3%3DCC4%3DNC%3DCN%3DC4C%3DC23 could not be loaded.