title: 7,11-Bis(4-methyl-phen-yl)-2,4,8,10-tetra-azaspiro-[5.5]undecane-1,3,5,9-tetra-one.
abstract: In the mol-ecule of the title compound, C(21)H(20)N(4)O(4), the two methyl-phenyl rings are oriented at a dihedral angle of 59.32 (4)°. The other two rings have flattened-boat conformations. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules. There are C-H⋯π contacts between a methyl-phenyl ring and methyl and methine groups.
authors.forename: Ali Mohammad
authors.initials: AM
authors.lastname: Astaraki
authors.forename: Ayoob
authors.initials: A
authors.lastname: Bazgir
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Faraji