3,4-Dibromo-2,5-bis­[(dieth­oxy­phosphor­yl)meth­yl]-1-phenyl­sulfonyl-1H-pyrrole

S Karthikeyan; K Sethusankar; Ganesan Gobi Rajeswaran; Arasambattu K Mohanakrishnan

doi:10.1107/S1600536811030273

. 2011 Aug 2;67(Pt 9):o2212–o2213. doi: 10.1107/S1600536811030273

3,4-Dibromo-2,5-bis[(diethoxyphosphoryl)methyl]-1-phenylsulfonyl-1H-pyrrole

S Karthikeyan ^a, K Sethusankar ^a,^*, Ganesan Gobi Rajeswaran ^b, Arasambattu K Mohanakrishnan ^b

PMCID: PMC3200636 PMID: 22064776

Abstract

In the title compound, C₂₀H₂₉Br₂NO₈P₂S, the pyrrole ring is essentially planar, with a maximum deviation of 0.013 (3) Å for a C atom. The pyrrole ring is almost orthogonal to the sulfonyl-bound phenyl ring, with a dihedral angle 88.5 (2)°. Both P atoms exhibit distorted tetrahedral configurations with O—P—O angles widened and O—P—C angles narrowed from the ideal tetrahedral value. In the crystal, molecules are linked into centrosymmetric dimers via C—H⋯O interactions, resulting in R ₂ ²(10) graph-set motifs which are further consolidated by R ₂ ²(13) graph-set ring motifs via C—H⋯O interactions, further resulting in chains of molecules running parallel to the c axis; a phosphono O atom is involved in bifurcated hydrogen bonding. All the ethoxy groups are disordered over two positions each with unequal site-occupancy factors.

Related literature

For a related structure, see: Seshadri et al. (2009 ▶). For applications of pyrrole derivatives, see: Faulkner (2002 ▶); Banwell et al. (2006 ▶); Fabio et al. (2007 ▶). For comparison of molecular dimensions, see: Bassindale (1984 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₀H₂₉Br₂NO₈P₂S
M _r = 665.26
Monoclinic,
a = 9.6524 (2) Å
b = 17.5137 (5) Å
c = 15.8965 (4) Å
β = 95.506 (1)°
V = 2674.89 (12) Å³
Z = 4
Mo Kα radiation
μ = 3.27 mm⁻¹
T = 293 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.440, T _max = 0.561
34672 measured reflections
8138 independent reflections
4819 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.121
S = 1.00
8138 reflections
355 parameters
20 restraints
H-atom parameters constrained
Δρ_max = 0.79 e Å⁻³
Δρ_min = −0.76 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811030273/pv2427sup1.cif

e-67-o2212-sup1.cif^{(41.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811030273/pv2427Isup2.hkl

e-67-o2212-Isup2.hkl^{(398.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811030273/pv2427Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5A⋯O6ⁱ	0.97	2.34	3.272 (4)	162
C16—H16⋯O3ⁱⁱ	0.93	2.44	3.162 (5)	134
C11—H11B⋯O6ⁱⁱⁱ	0.97	2.62	3.592 (19)	179

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

SK and KS thank Dr Babu Varghese, SAIF, IIT, Chennai, India, for the X-ray intensity data collection and Dr V. Murugan, Head of the Department of Physics, RKM Vivekananda College, for providing facilities in the department to carry out this work.

supplementary crystallographic information

Comment

Pyrrole derivatives are known to occur in many marine organisms (Faulkner, 2002). Pyrrole and its derivatives have shown to possess biological activities such as antibacterial, antiallergic, antitumor (Banwell, et al., 2006), and some of them are well known as metabotropic receptor antagonists (Fabio, et al.., 2007).

In the title compound (Fig. 1), the pyrrole ring is essentially planar with a maximum deviation of 0.013 (3)Å for atom C9. The methyl carbon atoms C5 and C10 and S1 atom lie -0.078 (3), 0.034 (3) and 0.5396 (8) Å, respectively, from the pyrrole plane. The pyrrole ring is almost orthogonal to the sulfonyl bound phenyl ring, with a dihedral angle 88.5 (2)°.

Atoms P1 and P2 have distorted tetrahedral configurations. The widening of angles O3—P1—O4 [114.4 (13)°] and O6—P2—O7 [120.0 (7)°] and narrowing of angles O5—P1—C5 [95.0 (9)°] and O8—P2—C10 [107.4 (9)°] from the ideal tetrahedral value are attributed to the Thrope-Ingold effect (Bassindale, 1984). The ethoxy side chains were disordered with un-equal site occupancy factors.

The crystal packing is stabilized by C—H···O intermolecular interactions. The molecules are linked into centrosymmetric dimers via C11—H11B···O6 interactions resulting in R²₂(10) graph set motif (Bernstein, et al., 1995). The dimers are further consolidated by R²₂(13) graph-set ring motif via C5—H5A···O6 and C16—H16···O3 interactions resulting in chains of molecules running parallel to the c-axis (Tab. 1 & Fig. 2); the phosphono O atom (O6) is involved in bifurcated hydrogen bonding.

Experimental

To a solution of 3,4-dibromo-2,5-bis(bromomethyl)-1-phenylsulfonyl- pyrrole (1 mmol) and triethylphosphite (2.5 mmol) in dry dichloromethane at room temperature, ZnBr₂ (0.4 mmol) was added and allowed to stir for 4 h under N₂. After consumption of the 3,4-dibromo-2,5-bis (bromomethyl)-1-phenylsulfonyl-pyrrole (monitored by TLC) volatile components were removed under vacuo. The residual mass was poured over crushed ice containing conc. HCl. The precipitated solid was filtered, washed with water and dried to give crude phosphonate ester which was crystallized from CHCl₃.