N,N,N′,N′-Tetrabenzyl-N′′-(2,6-difluorobenzoyl)phosphoric triamide

In the C(O)NHP(O) fragment of the title compound, C35H32F2N3O2P, the P—N bond is longer and the O—P—N angle is contracted compared with the other two P—N bonds and O—P—N angles. The P atom adopts a distorted tetrahedral environment and the phosphoryl and carbonyl groups are anti with respect to each other. The two tertiary N atoms of the dibenzylamido groups show sp 2 character with a slight deviation from planarity. In the crystal, pairs of N—H⋯O(P) hydrogen bonds form inversion dimers.


Related literature
H atoms treated by a mixture of independent and constrained refinement Á max = 0.28 e Å À3 Á min = À0.39 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). The phosphoryl and carbonyl groups, which are separated by an N atom, have a relative anti disposition. In the C(O)NHP(O) fragment, the P1-N1 bond is longer and the O2-P1-N1 angle is contracted compared with the other two P-N bonds and O-P-N angles, similar to what is found for related phosphoramide derivatives (Sabbaghi et al., 2010;Pourayoubi et al., 2010).
The two tertiary N atoms show sp 2 character with a slight deviation from planarity, wherein one of the two dibenzylamido N atoms shows a slightly greater deviation than the other [viz N3 with the sum of the surrounding bond angles = 353.48 (2)°]. The tertiary N3 atom is more pyramidal than N2 and is oriented so that the lone pair of electrons is anti with respect to the P═O group (Pourayoubi et al., 2012).
In the crystal, the hydrogen atom of the C(O)NHP(O) moiety is involved in an intermolecular N-H···O(P) hydrogen bond (see Table 1) to form an inversion dimer. Experimental 2,6-F 2 -C 6 H 3 C(O)NHP(O)Cl 2 was prepared according to a procedure reported by Pourayoubi et al. (2010).
To a solution of 2,6-F 2 -C 6 H 3 C(O)NHP(O)Cl 2 (1.5 mmol) in chloroform (25 ml), a solution of dibenzylamine (6 mmol) in chloroform (5 ml) was added at 273 K. After 4 h stirring, the solvent was removed and the product was washed with distilled water and recrystallized from a mixture of CH 3 OH/CHCl 3 (4:1 v/v) at room temperature.

Refinement
The hydrogen atom H1N was found in a Fourier difference map and was allowed to refine isotropically with the N-H distance constrained to 0.87 (2) Å and U iso (H) = 1.2 U eq (N). All other hydrogen atoms were placed in calculated positions with appropriate riding parameters.   An ORTEP-style plot and atom labeling scheme for the title compound. Displacement ellipsoids are given at 50% probability level and H atoms are drawn as small spheres with arbitrary radii.