Phosphorus heterocycles: synthesis, spectroscopic study and X-ray crystallography of some new diazaphosphorinanes

Abstract

New diazaphosphorinanes with formula C 6 H 5 OP(O)[NHCH 2 C(CH 3 ) 2 CH 2 NH] (1), RP(O)[NH(CH 2 ) 3 NH], R=C 6 H 5 O (2), 4-CH 3 -C 6 H 4 NH (3), 4-NO 2 -C 6 H 4 NH (4), RP(O)[NHC 10 H 6 NH],R=Cl (5), 4-CH 3 -C 6 H 4 O (6), and C 6 H 5 NH (7) were synthesized and characterized by 1 H, 13 C, 31 P NMR and IR spectroscopy and elemental analysis. The crystal structures of compounds 1 and 4-CH 3 -C 6 H 4 OP(O)[NH(CH 2 ) 3 NH] (8) were determined using X-ray crystallography. In these structures, the P=O bond is placed in an equatorial position and the aliphatic six-membered rings show chair conformations. These compounds form two-dimensional polymeric chains via intermolecular P=O…H-N hydrogen bonds. 1 H NMR spectrum of compound 1 shows a ddd splitting pattern for the coupling of H equatorial proton with phosphorus atom, H axial atom, and NH proton with a highvalue 3 J(PNCH) coupling constant = 26.1 Hz. But, H axial indicates a dd splitting pattern because of the coupling with H equatorial and NH protons. 13 C NMR spectra of compounds 5-7, indicated high values for 3 J(P,C) aromatic = 11.9, 11.3 and 10.2 Hz due to the coupling of the aromatic carbon atom of naphthalene moiety with the phosphorus atom. 31 P NMR spectra indicate that the d( 31 P) of compounds 1-4 and 8 containing NH groups connected to the aliphatic carbon atoms appear downfield relative to those of compounds 5-7 that containing NH groups connected to the aromatic naphthalene group.Graphical abstract 4-CH 3 -C 6 H 4 OP(O)[NH(CH 2 ) 3 NH]

Polymorphism for a novel phosphoramidate; NMR and X-ray crystallography

“…Similar results were obtained for the nitrogen atoms of structure 2b that confirm the sp 2 hybridization for the N atoms, although due to the repulsion and steric interactions, some angles are greater, and others are smaller than 120°. This observation suggests the existence of partial multiple bond character between phosphorus and nitrogen atoms that has always been confirmed by the crystallographic data of our previously reported similar compounds [29][30][31][32][33][34].…”

The first naphthodiazaphosphorinane in the solid phase; syntheses, spectroscopic studies and X-ray crystallography of some new 1,3,2-diheterophosphorus compounds

“…Nowadays, modification of cyclophosphamide (an oxazaphosphorinane compound) have led to the design and synthesis of numerous cyclic analogous compounds [4][5][6][7][8] to find an antitumor agent that has less side effects than drugs now present. The chemistry of 1,3,2-oxaza- [9,10] and dioxa-phosphorinanes [11,12], as well as the synthesis [13,14], stereochemistry [15], coordination chemistry [16,17] and, X-ray crystal structures [4,18] of 1,3,2-diazaphosphorinanes have frequently been studied.…”

Synthetic Approach for Novel Fluorine Substituted <i>α</i>-Aminophosphonic Acids Containing 1,2,4-Triazin-5-One Moiety as Antioxidant Agents

“…Also, the chemistry of N-phosphoryl heterocyclic indicates that these compounds form dimensional polymeric chain via intermolecular P-O − ······ + NH hydrogen bond [2]. Moreover, the reactivity of the dipolar ion structures of the tautomeric form of α-amino phosphonates is due to the higher electron-withdrawing properties of two phenoxy and P=O groups.…”