Crystal structure of N-diphenylphosphoryl-4-bromoaniline, C18H15BrNOP

Abstract

C 18 H 15 BrNOP, monoclinic, P2 1 /n (no. 14), a =12.441(3) Å, b =8.949(2) Å, c =15.180(3) Å, b =102.87(3)°, V =1647.6 Å 3 , Z =4,Rgt(F) =0.049, wRref(F 2 ) =0.107, T =293 K. Source of materialAll commercially available reagents were used as supplied. Asolution of Ph 2 PCl (2.2 g, 10 mmol) in Et 2 O( 10 mL) was added dropwise to asolution of 4-bromoaniline (1.7 g, 0.1 mmol) and Et 3 N(2.0 mL) in 30 mL Et 2 Oatroom temperature. The resulting white suspension was stirred for 3h ,t he solvent evaporated to dryness and obtianed the crude intermediate (4-BrC 6H4)NPPh2 solid. Then the solid was dissolved in 30 mL THF. 0.5 mL aqueous H 2 O 2 (30 %, w/w)was added and stirred for 5h.The solution was evaporated to dryness under reduced pressure to give the title compound as aw hite solid (yield: 2.8 g, 7.5 mmol, 75.5 .%). Elemental analysis -found: C, 58.21 %; H, 3.92 %; N, 3.95 %; calculated for C 18H15BrNOP: C, 58.09 %; H, 4.06 %; N, 3.76 %. Colorless block-shaped single crystals of the title compound suitable for X-ray structure determination were obtained by slow evaporation of the ethanol solution at room temperature after one week. Experimental detailsHydrogen atoms were placed in calculated positions with d(C-H) =0.93 Å (aromatic) and d(N-H) =0.86 Å,and were refined in riding mode. The U iso (H) values were set at 1.2 U eq (C,N). DiscussionThe crystal structure of the title compound is similar to that observed in N-diphenylphosphorylaniline [1] and N-diphenylphosphoryl-2-cyanoaniline [2]. The phosphorus adopts ad istorted tetrahedral environment (figure, top), and the P-Oa nd P-Cdistances are within the normal ranges [1,2]. In addition, inter-molecular hydrogen bonding via P=O···H-Nexists in the title compound, thus resulting in azigzag arrangement in the lattice (figure, bottom).