ERROR opening https://cactus.nci.nih.gov/chemical/structure/n4nc%28N1CCNCC1%29n5c2ccccc2Cc3ccccc3c45/file?format=sdf&get3d=True  -- n4nc%28N1CCNCC1%29n5c2ccccc2Cc3ccccc3c45 could not be loaded.