ERROR opening https://cactus.nci.nih.gov/chemical/structure/c3c1OCOc1ccc3C%28%3DO%29C%28C%29N2CCCC2/file?format=sdf&get3d=True  -- c3c1OCOc1ccc3C%28%3DO%29C%28C%29N2CCCC2 could not be loaded.