New phosphoric triamides: Chlorine substituents effects and polymorphism

New phosphoric triamides 1–10 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, and IR spectroscopy and elemental analysis. Surprisingly, the ¹H NMR spectra of compounds 1–7 demonstrate long‐range ⁴J(H,H) coupling constant from 1.5 to 1.9 Hz. Comparison of the NMR and IR spectra of N‐benzoyl, N‐4‐chlorobenzoyl, and N‐2,4‐dichlorobenzoyl phosphoric triamide analogues indicates that N‐2,4‐dichlorobenzoyl derivatives have the most upfield δ(³¹P) and the highest ν(CO) values. The crystal structures of 3 , 4 , 6 , 6a , and 10 have been determined by X‐ray crystallography. Interestingly, the structures of 6 and 6a are polymorphic. All structures form dimers through strong, intermolecular  PO···H N hydrogen bonds. The dimers connect to each other via weak C H···Cl and C H···OH bonds to produce two‐dimensional polymeric chains for 4 and three‐dimensional networks for others. Among new synthesized N‐2,4‐dichlorobenzoyl phosphoric triamides, one indicated polymorphism. All structures were characterized by ¹H, ¹³C, ³¹P NMR, and infrared spectroscopy and elemental analysis. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:168–180, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20592