Research Article

X-Ray Single Crystal Structure Of 6- Phenyl-6-Selanylidene-13,13a Dihydro-6H, 8H-6λ5-Quinazolino [3,2 c ][1,3,2] Benzoxazaphosphinin-8-One

Neetu, Saima Naz and Arif Ali Khan*

University School of Basic & Applied Sciences, Guru Gobind Singh Indraprastha, University, Dwarka, Sector 16-C, New Delhi, India

Submission: August 29, 2023;Published: September 07, 2023

*Corresponding author: Arif Ali Khan, University School of Basic & Applied Sciences, Guru Gobind Singh Indraprastha, University, Dwarka, Sector 16-C, New Delhi, India

How to cite this article: Neetu, Saima N, Arif Ali K. X-Ray Single Crystal Structure Of 6-Phenyl-6-Selanylidene-13,13a Dihydro-6H,8H-6λ5-Quinazolino [3,2 c ][1,3,2] Benzoxazaphosphinin-8-One. Organic & Medicinal Chem IJ. 2023; 12(5): 555846. DOI: 10.19080/OMCIJ.2023.12.555846

Abstract

The title compound(C20H15N2O2PSe) is synthesized and characterized by NMR, IR, GC-MS and single crystal X-ray diffraction. It has triclinic (P1̅) symmetry with unit cell parameters: a=8.1901 (5) Å, b= 10.6528 (5) Å, c= 11.8017 (8) Å, α=65.547 (1) °, β= 74.393 (2) °, γ = 80.434 (1) ° In this crystal structure, one P-atom attached with Se atom, one phenyl ring, one O-atom and one N-atom. The bond angles for Se—P—atom are 112.64 (6) °, 116.30 (7) °, 119.31(8) ° with O2, N1, C14 respectively. The P=Se bond length is 2.0735(7) Å. The other bond lengths are 1.612(1) Å, 1.685(2) Å, 1.793(2) Å for P1—O2, P1—N1, P1—C14 respectively.

Keywords: Single Crystal; Benzoxazaphosphinine; Selanylidene; Antibacterial

Introduction

Organophosphorus heterocycles like oxazaphosphinines with O and N in six-membered rings exhibit strong antitumor [1] and antibacterial activity [2]. As a result, there is a great deal of interest in drug design and synthesis [3] due to the therapeutic importance and stereochemical properties of oxazaphosphinines. The single crystal structure of the title compound is being reported as part of our research in this area (C₂₀H₁₅N₂O₂PSe).

Material and Methods

The synthesis, crystallisation, and spectroscopic studies of novel 6-phenyl-6-selanylidene 13,13a-dihydro-6H,8H-6λ5-quinazolino[3,2-c][1,3,2]benzoxazaphosphinin-8-one has been reported previously [4]. In a reaction mixture of 6-Phenyl-12,12a-dihydro-5-oxa-6a,12-diaza-6-phospha-benzo[a]anthracen-7-one in toluene , an access of selenium powder (0.77 g, 10 mmol) was added and refluxed for 5 h. The resulting dark red colour solution was filtered hot under inert atmosphere and concentrated under reduced pressure. The crude product was crystallized with diethyl ether. (Melting point- 160-170o C); 31P-NMR(161.5 MHz, CDCl₃): δ 73.4 (t) (¹J_P=Se : 895.66Hz); 13C-NMR (100 MHz, CDCl₃): δ 165, 148, 146, 137, 135, 133, 132, 131, 129, 128, 125, 121, 117, 67, 45; 1H-NMR (400 MHz, CDCl₃): δ 6-8(m,13H), δ 4(broad, NH); IR Data: 578.64(P=Se), 1670.35 (C=O Stretching), 3282.84 (2o NH Stretching); MS (EI, 30 eV)m/z= 424 (62%, M+), , 267 (100%, base peak).

Single Crystal X-Ray Diffraction

A suitable single crystal of title compound for data collection was selected and data were collected at 273K by ω scan technique on three circle Bruker SMART diffractometer with CCD area detector using graphite monochromate radiation MoKα (λ=0.71073Å) from sealed X-ray tube diffraction source. The data collection was performed by using the Bruker APEX2 [5]. The data reduction and cell refinement were performed using the Bruker SAINT [6]. Molecular graphics was performed by using Olex2 1.5 [7]. The figures were produced using ORTEP [8] and PLATON [9]. Table 1 contains an overview of the crystal data, experimental details, and refining results.

Geometric Parameters

The bond lengths are given in table 2, bond angles are given in table 3. And torsion angles are given in table 4.

Result And Discussion

Structure Description

The structure of the title compound has triclinic (P1̅) symmetry, in which one P-atom attached with Se-atom, one phenyl ring, one O-atom and one N-atom. The structure has 5 six member rings, in which 3 rings are almost coplanner and the two saturated rings which have heteroatoms are out of the plane due to rigidity (Figure 1-3). The bond angles for Se—P—atom are 112.64 (6)°, 116.30 (7)°, 119.31(8)° with O2, N1, C14 respectively. The P=Se bond length is 2.0735(7) Å the other bond lengths are 1.612(1), 1.685(2), 1.793(2) Å for P1—O2, P1—N1, P1—C14 respectively. The dihedral angle between the planes produce through the bonded atoms of two aromatic rings (C14---C19 and C2---C7) is 71.73°, dihedral angle between the planes produce through the bonded atoms of the aromatic ring(C14---C19) and heterocyclic ring (N1-C8-C20-C9-P1-O2) is 86.26°, and dihedral angle between the planes produce through the bonded atoms of the aromatic ring (C2---C7) and heterocyclic ring (N1-C8-C20-C9-P1-O2) atoms is 38.34° (Figure 4).

Supramolecular Feature

The intermolecular hydrogen-bonding is observed in this molecule, which may help to stabilize the crystal structure of molecule (Figure 5).In the crystal, the molecules are held together by an intermolecular interactions of the types C15Times New RomanH15---N2 hydrogen-bond between the phenyl C⸺H and the pyrimidine nitrogen atom, C18⸺H18---O2 hydrogen bond between the phenyl CTimes New RomanH and the phosphorus heterocyclic ring oxygen atom and C6⸺H6---O1 hydrogen-bond between the phenyl C⸺H and the carbonyl oxygen atom (Table 5).

Supplementary Information

CCDC 2192461 contains crystallographic supplementary data for this paper.

Conclusion

The structure of the title compound has triclinic (P1̅) symmetry. The bond angles for Se—P—atom are 112.64 (6)°, 116.30 (7)°, 119.31(8) °with O2, N1, C14 respectively. The P=Se bond length is 2.0735(7) Å. The other bond lengths are 1.612(1), 1.685(2), 1.793(2) Å for P1—O2, P1—N1, P1—C14 respectively. The dihedral angle between the planes produce through the bonded atoms of two aromatic rings (C14---C19 and C2---C7) is 71.73°, dihedral angle between the planes produce through the bonded atoms of the aromatic ring(C14---C19) and heterocyclic ring (N1-C8-C20-C9-P1-O2) is 86.26°, and dihedral angle between the planes produce through the bonded atoms of the aromatic ring (C2---C7) and heterocyclic ring (N1-C8-C20-C9-P1-O2) atoms is 38.34°.

The intermolecular hydrogen-bonding is observed in this molecule, which may help to stabilize the crystal structure of molecule. In the crystal, the molecules are held together by an intermolecular interactions of the types C15-H15---N2 hydrogenbond between the phenyl C-H and the pyrimidine nitrogen atom, C18-H18---O2 hydrogen bond between the phenyl C-H and the phosphorus heterocyclic ring oxygen atom and C6-H6---O1 hydrogen-bond between the phenyl C-H and the carbonyl oxygen atom.

Acknowledgement

Authors are thankful to Guru Gobind Singh Inderprastha University for providing FRGS Grant to carry out this research work.

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