N,N′-Dibenzyl-N′′-(4-bromobenzoyl)-N,N′-dimethylphosphoric triamide

In the title compound, C23H25BrN3O2P, the P atom has a distorted tetrahedral coordination. In the crystal structure, the molecules form centrosymmetric dimers via pairs of essentially linear N—H⋯O hydrogen bonds.

In the title compound, C 23 H 25 BrN 3 O 2 P, the P atom has a distorted tetrahedral coordination. In the crystal structure, the molecules form centrosymmetric dimers via pairs of essentially linear N-HÁ Á ÁO hydrogen bonds.
SD acknowledges the Alzahra University Research Council for partial support of this work.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZL2095). N,   (Trush et al., 2003;Gubina et al., 2000), as prodrugs in pharmacology and as pesticides in agriculture (Barak et al., 2000;Mallender et al., 2000). A thorough knowledge of the structural properties of these compounds should be beneficial for a detailed understanding of their pharmacological effects. The title compound, (I), was prepared by the reaction of (pBr-C 6 H 5 )C(O)NHP(O)(Cl) 2 with two molecules of methylmenzyl amine.
The crystal structure of (I) reveals that, in the molecular core unit C(O)NHP(O), the C(O) and P(O) oxygen atoms are in anti-positions to each other. The phosphorus centre has a slightly distorted tetrahedral coordination, mainly due to the presence of the different substituents. The N3-P1-N1 angle (105.20 (12)°) is narrower than the ideal tetrahedral angle of 109.5, whereas the opposite O2-P1-N3 angle (119.05 (13)°) is wider than the ideal tetrahedral angle. The P1-O2 bond length (1.474 (2) Å) is in good agreement with P-O distances in other carbacylamidophosphates (Trush et al., 1999).
Examination of intermolecular distances indicates that the crystal structure of compound (I) consists of C 9 H 13 N 2 O 2 P units linked together via N-H···O hydrogen bonds into centrosymmetric dimers featuring eight-membered (OPNH) 2 rings Table 1).

Experimental
Compound (I) was synthesized via the reaction of BrC 6 H 4 C(O)NHP(O)Cl 2 with two molecules of methylbenzylamine in a 1:4 molar ratio. Methylbenzylamine was added dropwise to a mixture of BrC 6 H 4 C(O)NHP(O)Cl 2 in chloroform while stirring at room temperature for 4 h. The product was filtered off and then washed with cold water. The compound was recrystallized from ethanol (yield 88%). Analysis, calculated for C 23 H 25 Br N 3 O 2 P: C 56.80, H 5.18, N 8.64%; found: C 56.81, H 5.19, N 8.64%.

Refinement
H atoms were placed in idealized positions with C-H distances at 0.97, 0.96 and 0.93 Å for CH 2 , CH 3 and aromatic CH groups, respectively using a riding model. U iso (H) for H was assigned as 1.2 U eq (Ci) of the attached C atoms (1.5 for methyl). No absorption correction was applied due to the small cystal size and the sufficiently low µ value.