N,N'-Dicyclo-hexyl-N,N'-dimethyl-N''-(4-nitro-benzo-yl)phospho-ric triamide.

The P atom in the title compound, C(21)H(33)N(4)O(4)P, is in a slightly distorted tetra-hedral coordination environment and the phosphoryl and carbonyl groups are anti to each other. The environment of each N atom is essentially planar (average angles of 119.9 and 118.4°). In the crystal structure, the H atom of the C(=O)NHP(=O) group is involved in an inter-molecular -P=O⋯H-N- hydrogen bond, forming centrosymmetric dimers.