trans-1-Phenyl­pyrrolidine-2,5-dicarbo­nitrile

Wei Han; Armin R Ofial; Peter Mayer

doi:10.1107/S1600536810001479

. 2010 Jan 16;66(Pt 2):o379. doi: 10.1107/S1600536810001479

trans-1-Phenylpyrrolidine-2,5-dicarbonitrile

Wei Han ^a, Armin R Ofial ^a, Peter Mayer ^a,^*

PMCID: PMC2979938 PMID: 21579801

Abstract

In the title compound, C₁₂H₁₁N₃, the plane of the phenyl ring and the least-squares plane of the pyrrolidine ring enclose an angle of 14.30 (6)°. The intracyclic N atom features a nearly trigonal-planar coordination geometry due to π-interactions with the aromatic system. The pyrrolidine ring is present in a twist conformation for which the closest pucker descriptor is ^C9 T _C8. Weak intermolecular C—H⋯N and C—H⋯π contacts occur

Related literature

For background to the synthesis, see: Han & Ofial (2009 ▶); Takahashi et al. (1986 ▶). For a related structure, see: Menezes et al. (2007 ▶). For puckering analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₂H₁₁N₃
M _r = 197.24
Orthorhombic,
a = 9.1807 (1) Å
b = 14.5693 (2) Å
c = 15.7576 (2) Å
V = 2107.68 (5) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 200 K
0.33 × 0.18 × 0.15 mm

Data collection

Nonius KappaCCD diffractometer
16161 measured reflections
2413 independent reflections
2109 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.107
S = 1.06
2413 reflections
136 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: COLLECT (Hooft, 2004 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO (Otwinowski & Minor, 1997 ▶) and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810001479/fl2285sup1.cif

e-66-0o379-sup1.cif^{(16.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810001479/fl2285Isup2.hkl

e-66-0o379-Isup2.hkl^{(118.7KB, hkl)}

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

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

Cg is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯N2ⁱ	0.95	2.70	3.5952 (17)	158
C8—H8B⋯N2ⁱⁱ	0.99	2.67	3.3777 (17)	129
C10—H10⋯N3ⁱⁱⁱ	1.00	2.69	3.3748 (15)	126
C8—H8A⋯Cgⁱ	0.99	2.74	3.6937 (13)	162
C9—H9B⋯Cg^iv	0.99	2.88	3.5111 (13)	122

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

Acknowledgments

We thank the Chinese Scholarship Council for a fellowship (to WH) and Professor Herbert Mayr for continuous support.

supplementary crystallographic information

Comment

Under oxidative conditions, iron salts activate C(sp³)-H bonds adjacent to the nitrogen atom of tertiary amines. Hence the cross-coupling reactions of a variety of tertiary amines with cyanide were enabled in the presence of tert-butylhydroperoxide. Performing the reaction in the presence of 4 equivalents of trimethylsilyl cyanide allowed the twofold cyanation of N-phenylpyrrolidine [Han et al. (2009)].

The asymmetric unit of (I) contains one complete molecule which is shown in Figure 1. The plane of the phenyl ring and the least-square plane of the pyrrolidine ring enclose an angle of 14.30 (6)°, which is quite similar to the angle found in a related structure of 1,2-Dichloro-4-(pyrrolidino)-5-nitrobenzene (18.69 (14)°, Menezes et al. (2007)).

The intracyclic nitrogen atom is nearly in the plane defined by the three carbon atoms bonded to it. The displacement of the nitrogen atom from the plane is only 0.073 (1) Å. The planarization of the nitrogen atom may be rationalized by possible π-interaction of the lone pair with the aromatic system.

The pyrrolidine ring is present in a twist-conformation for which the closest pucker descriptor is ^C9T_C8 [Cremer et al. (1975)]. This conformation is slightly distorted towards an envelope-conformation E_C8. In a related structure [Menezes et al. (2007)], the ring is twisted along the same bond, however, in the other direction (^C8T_C9).

Both carbonitrile nitrogen atoms act as acceptors in very weak contacts of the type C–H···N. Furthermore the packing features very weak C–H···π contacts with the phenyl π-system as acceptor. The packing of the title compound is shown in Figure 2.

Experimental

Under an atmosphere of dry nitrogen, a 25 ml Schlenk flask was charged with FeCl₂ (10 mol-/%, 13 mg). Then N-phenylpyrrolidine (1.0 mmol), trimethylsilyl cyanide (4.0 mmol, 0.54 ml), and MeOH (2.0 ml) were added successively by syringe. To the mixture was added dropwise tert-butylhydroperoxide (2.5 mmol, 0.470 ml, 5.5 M solution in decane) over a period of 5 minutes. The mixture was stirred at room temperature for 24 h. Subsequently, the reaction mixture was poured into a saturated aqueous NaCl solution (20 ml) and extracted with dichloromethane (three times 20 ml). The organic phases were combined, and the volatile components were evaporated in a rotary evaporator. After column chromatography on silica gel (n-pentane/diethyl ether = 3:1, v/v), 1-phenylpyrrolidine-2,5-dicarbonitrile was isolated as a colorless solid (54%) [Han et al. (2009)].

The title compound (50 mg) was dissolved in 2 ml of a mixture of dichloromethane/n-pentane/ethyl ether mixture (2/1/1, v/v/v). The solvent was allowed to evaporate slowly at room temperature. The thus formed crystals were suitable for X-ray analysis. mp 149–151 °C ([Takahashi et al. (1986)], mp 161.5–163 °C (from ethanol)).