4-Chloro-7-methoxy­methyl-2-phenyl-7H-pyrrolo[2,3-b]pyridine

Roland Selig; Dieter Schollmeyer; Wolfgang Albrecht; Stefan Laufer

doi:10.1107/S1600536810008822

. 2010 Mar 13;66(Pt 4):o822. doi: 10.1107/S1600536810008822

4-Chloro-7-methoxymethyl-2-phenyl-7H-pyrrolo[2,3-b]pyridine

Roland Selig ^a, Dieter Schollmeyer ^b, Wolfgang Albrecht ^c, Stefan Laufer ^a,^*

PMCID: PMC2983947 PMID: 21580653

Abstract

In the title compound, C₁₅H₁₃ClN₂O, the phenyl group makes a dihedral angle of 7.91 (8)° with the pyrrole ring. The crystal structure forms a three-dimensional network stabilized by π–π interactions [centroid–centroid distances = 3.807 (1) Å] between the pyridine and phenyl rings and via intermolecular C—H⋯O hydrogen bonds.

Related literature

Chlorination of 2-phenyl-1H-pyrrolo[2,3-b]pyridine was performed by an analogous procedure, see: Layek et al. (2009 ▶).

Experimental

Crystal data

C₁₅H₁₃ClN₂O
M _r = 272.72
Orthorhombic,
a = 8.4785 (8) Å
b = 9.6576 (10) Å
c = 15.8560 (16) Å
V = 1298.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 173 K
0.32 × 0.21 × 0.08 mm

Data collection

Bruker SMART APEXII diffractometer
5977 measured reflections
3084 independent reflections
2667 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.079
S = 1.03
3084 reflections
173 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.22 e Å⁻³
Absolute structure: Flack (1983 ▶), 1299 Friedel pairs
Flack parameter: 0.02 (6)

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: SAINT (Bruker, 2006 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810008822/bt5211sup1.cif

e-66-0o822-sup1.cif^{(17.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810008822/bt5211Isup2.hkl

e-66-0o822-Isup2.hkl^{(151.4KB, hkl)}

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—H5⋯O15ⁱ	0.95	2.32	3.237 (2)	162

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors would like to thank the Federal Ministry of Education and Research, Germany, Merckle GmbH, Ulm, Germany, and the Fonds der Chemischen Industrie, Germany, for their generous support of this work.

supplementary crystallographic information

Comment

N-protection of 7-azaindoles is a often used and necessary procedure for further NH sensitive reactions. Many protecting procedures with 4-chloro-1H-pyrrolo[2,3-b]pyridine are kown in literature. By N-protection of 4-chloro-2-phenyl-1H-pyrrolo[2,3-b]pyridine with methoxymethylchloride, two regioisomeres are formed, the expected 4-chloro-1-(methoxymethyl)-2-phenyl-1H-pyrrolo[2,3-b]pyridine and the title compound in a ratio of 1:1.6. The title compound and its regioisomer demonstrate the delocalization of the deprotonated anionic 4-chloro-1-(methoxymethyl)-2-phenyl-1H-pyrrolo[2,3-b]pyridine species. The phenyl moiety encloses a dihedral angle of 7.91 (8)° toward the azaindole system. The crystal structure is characterized by intermolecular hydrogen bond C5—H5···O15 (2.32 Å) and intramolecular hydrogen interactions C13—H13···N1 (2.54 Å), C14—H14B···N1 (2.48°). Stabilization of the three dimensional network is performed by π -π interactions between the pyridine and the phenyl rings with centroid distances of 3.807 (1) Å (symmetry operator 1.5-x, 1-y, -0.5∓z).

Experimental

2,5 g (11 mmol) 4-chloro-1-(methoxymethyl)-2-phenyl-1H-pyrrolo[2,3-b]pyridine was dissolved in dry THF (15 ml). After addition of 0.61 g (15 mmol) NaH (60% in mineral oil) the reaction mixture was stirred for 15 minutes at room temperature. 7.3 ml (15 mmol) methoxymethylchloride (2.1M in toluene) was added and the mixture was stirred for further 15 minutes. The reaction mixture was quenched with concentrated aqueous ammonium chloride solution. After extraction with ethyl acetate, the crude product was purified by flash chromatography. Crystals suitable for X-ray analysis were obtained by slow crystallisation from methanol.