N,N′-Dibenzyl-N,N′-dimethyl-N′′-(p-tolyl)phosphoric triamide

The asymmetric unit of the title compound, C23H28N3OP, contains two independent molecules with significant conformational differences. For example, the torsion angles N—C—C—C involving the N-benzyl moieties are 57.3 (7) and 11.6 (8)° in one molecule and 76.5 (7) and 97.4 (7)° in the other. In each molecule, the P atom exhibits a distorted tetrahedral conformation [the bond angles at P are in the ranges 104.7 (2)–115.2 (2) and 105.1 (2)–115.1 (2)° in the two molecules], and the phosphoryl group and the N—H group adopt an anti orientation with respect to one another. In the crystal, molecules are linked via N—H⋯O(P) hydrogen bonds, forming a chain parallel to the a axis.

The asymmetric unit of the title compound, C 23 H 28 N 3 OP, contains two independent molecules with significant conformational differences. For example, the torsion angles N-C-C-C involving the N-benzyl moieties are 57.3 (7) and 11.6 (8) in one molecule and 76.5 (7) and 97.4 (7) in the other. In each molecule, the P atom exhibits a distorted tetrahedral conformation [the bond angles at P are in the ranges 104.7 (2)-115.2 (2) and 105.1 (2)-115.1 (2) in the two molecules], and the phosphoryl group and the N-H group adopt an anti orientation with respect to one another. In the crystal, molecules are linked via N-HÁ Á ÁO(P) hydrogen bonds, forming a chain parallel to the a axis. 508 parameters H-atom parameters constrained Á max = 0.32 e Å À3 Á min = À0.33 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). N, N'-Dibenzyl-N,N'-dimethyl-N''-(p-tolyl)phosphoric triamide M. Pourayoubi, B. Elahi and M. Parvez

Comment
In continuation of our investigations on the synthesis of new phosphoramidates (Toghraee et al., 2011;Pourayoubi et al., 2011) we now report the synthesis and crystal structure of the title phosphoric triamide.
The asymmetric unit of the title compound ( Fig. 1) contains two independent molecules with significant conformational differences. The torsion angles N1-C2-C3-C4 and N2-C10-C11-C16 involving the N-benzyl moiety in one molecule are: 57.3 (7) and 11.6 (8)°, respectively, compared to the corresponding angles in the second molecule with values 76.5 (7) and 97.4 (7)° (for torsion angles N5-C33-C34-C35 and N4-C25-C26-C31, respectively). In each molecule, the P atom adopts a distorted tetrahedral coordination P(═O)(N)(N) 2 environment with the bond angles in the range of 104.7 (2)° to 115.2 (2)°f or P1 and 105.1 (2)° to 115.1 (2)° for P2. The P═O and P-N bond lengths and the P-N-C bond angles are within the expected values for analogous compounds reported in the literature (Gholivand et al., 2011). In both molecules, the P-N In the crystal packing, the molecules are hydrogen bonded to each other resulting in a chain along to the a axis in an alternating sequence (Fig. 2).

Experimental
To a solution of 4-CH 3 -C 6 H 4 NHP(O)Cl 2 in chloroform, a solution of N-methylbenzylamine in chloroform was added dropwise at 273 K. After stirring for 4 h, the solvent was evaporated at room temperature and the obtained solid was washed with distilled water to remove N-methylbenzylamine hydrochloride salt. Single crystals, suitable for X-ray crystallography, were obtained from a solution of title compound in chloroform after slow evaporation at room temperature.

Refinement
The H-atoms were included at geometrically idealized positions with N-H distances 0.88 Å and C-H distances = 0.95, 0.98 and 0.99 Å for aryl, methyl and methylene type H-atoms, respectively. The methyl H-atoms at C1 were disordered over six sites with equal site occupancy factors. The H-atoms were assigned U iso = 1.5 times U eq C1 atom and 1.2 times U eq of the rest of the parent atoms (C/N). The ADSYMM option in Platon suggests a pseudo-translation in the direction of the c-axis. Indeed the structure can also be refined in the subcell which leads to a strong disorder of the phenyl rings and practically no improvement of the reliability factors. This is in agreement with the results of the structure determination of the supercell, which shows that the torsion of the phenyl rings is different. Therefore, we decided to perform the refinement in the supercell. In this context it is noted that the intensity of the super structure reflections is very low and therefore, only about 60% of all independent reflections are observed, which might also be responsible for the low reliability factors. Fig. 1. An ORTEP plot of the title molecule with labeling. Displacement ellipsoids are given at 50% probability level.   (7) 0.0050 (7) 0.0011 ( 0.0239 (7) 0.0327 (9) 0.0204 (7) −0.0018 (7) 0.0021 (6) 0.0029 (7)