ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%3D3NN%28c1ccccc1%29C%28%3DO%29C%3D3/N%3DN/c2ccccc2/file?format=sdf&get3d=True  -- CC%3D3NN%28c1ccccc1%29C%28%3DO%29C%3D3/N%3DN/c2ccccc2 could not be loaded.