ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28N%28c1ncccc1%29C%28CN2CCCCC2%29C%29CC/file?format=sdf&get3d=True  -- O%3DC%28N%28c1ncccc1%29C%28CN2CCCCC2%29C%29CC could not be loaded.