ERROR opening https://cactus.nci.nih.gov/chemical/structure/N%5C2%3DC1/SCCN1C%5BC%40%40H%5D/2c3ccccc3/file?format=sdf&get3d=True  -- N%5C2%3DC1/SCCN1C%5BC%40%40H%5D/2c3ccccc3 could not be loaded.