ERROR opening https://cactus.nci.nih.gov/chemical/structure/c4ncccc4-c%28c2%29cccc2-n3c1ccc%28cc1nc3%29C%28C%29%3DNOCC/file?format=sdf&get3d=True  -- c4ncccc4-c%28c2%29cccc2-n3c1ccc%28cc1nc3%29C%28C%29%3DNOCC could not be loaded.