ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCCCOc1ccccc1/C%28%3DC%5CSC%29/n2ccnc2/file?format=sdf&get3d=True  -- CCCCCOc1ccccc1/C%28%3DC%5CSC%29/n2ccnc2 could not be loaded.