ERROR opening https://cactus.nci.nih.gov/chemical/structure/c1c4c%28cc2nccnc12%29%5BC%40%40H%5D3C%5BC%40H%5D4CNC3/file?format=sdf&get3d=True  -- c1c4c%28cc2nccnc12%29%5BC%40%40H%5D3C%5BC%40H%5D4CNC3 could not be loaded.