ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28c2cc1nnnc1cc2OC%29NCC3N%28C%5CC%3DC%29CCC3/file?format=sdf&get3d=True  -- O%3DC%28c2cc1nnnc1cc2OC%29NCC3N%28C%5CC%3DC%29CCC3 could not be loaded.