N-2,4-dichlorobenzoyl phosphoric triamides: Synthesis, spectroscopic and X-ray crystallography studies

Abstract

New phosphoric triamides 1–9 were synthesized by the reaction of N-2,4-dichlorobenzoyl phosphoramidic dichloride with various cyclic aliphatic amines and the products were characterized by 1H, 13C, 31P NMR, IR spectroscopy and elemental analysis. Surprisingly, the 1H NMR spectrum of 2 indicated long range 6 J (P, H) coupling constant = 1.3, 1.4 Hz and those of molecules 3, 4, 6–8 display long-range 4 J (H, H) coupling constants (1.8–1.9 Hz) for the coupling of aromatic protons in 2,4-dichlorophenyl rings. 1H NMR spectra indicated 3 J (PNCH) for enantiotopic and diastereotopic benzylic CH2 protons in compounds 7 and 8. The spectroscopic data of newly synthesized compounds were compared with those related N-benzoyl derivatives. The structures of compounds 5, 8 and 10 (2,4-Cl2-C6H3C(O)NHP(O)[NCH2CH(CH3)2]2) have been determined by X-ray crystallography. The structures form centrosymmetric dimers through intermolecular strong -P=O…H-N-hydrogen bonds. The dimers connect to each other via rather strong and weak C-H…O plus weak C-H…Cl H-bonds to produce a 1-D network for 5 while 3-D polymeric chains for 8 and 10.