1,2-diacetyl-4-phenyl-1,2,4-triazolidine-3,5-dione

The title crystal, C12H11N3O4, contains three essentially identical molecules in the asymmetric unit. The triazole rings in the three independent molecules are planar within 0.014 A. The N atom containing the phenyl substituent is trigonal, the sum of the three bond angles being 359.5 degrees. The other two N atoms are slightly pyramidal, the sum of the three bond angles being 346 degrees. The two acetyl groups are twisted out of the plane of the triazole ring by an average of 33 degrees and are trans to each other.