N-[1-(1H-Pyrrol-2-yl)ethylidene]aniline

There are two independent molecules in the asymmetric unit of the title compound, C12H12N2, in which the pyrrole and benzene rings form dihedral angles of 72.37 (7) and 82.34 (8)°. The imino N—C bond lengths in the two molecules are equal [1.286 (2) Å] and indicate C=N character. In the crystal, each molecule forms a dimer with an inversion-related molecule through a pair of classical N—H⋯N hydrogen bonds.

There are two independent molecules in the asymmetric unit of the title compound, C 12 H 12 N 2 , in which the pyrrole and benzene rings form dihedral angles of 72.37 (7) and 82.34 (8) . The imino N-C bond lengths in the two molecules are equal [1.286 (2) Å ] and indicate C N character. In the crystal, each molecule forms a dimer with an inversion-related molecule through a pair of classical N-HÁ Á ÁN hydrogen bonds.

Comment
In recent years, the bis(imino)pyridine incorporated late transition metal catalysts have received considerable attention because of their antioxidant property and outstanding activity for olefin polymerization (Small et al., 1998;Su et al., 2009a,b). As the five-memberd ring substitute of pyridine six-memberd ring (Matsuo et al., 2001;He et al., 2009), pyrrole was frequently introduced into the skeleton of bis(imino)pyridine ligand to design new ligand and corresponding metal complexes (Britovsek et al., 2003;Dawson et al., 2000). Bis(imino)pyrrole was usually prepared from Schiff base condensation of 2,5-diacetylpyrrole and the aromatic amine (Matsuo et al., 2001). As a contribution to this research field, we report herein the synthesis of mono(imino)pyrrole from 2-acetyl pyrrole and aromatic anime, as well as the crystal structure of the title compound 2-(1-phenyliminoethyl)pyrrole.
The asymmetric unit of the title compound ( Fig. 1)

Experimental
The 2-acetyl pyrrole (0.1313 g, 1.20 mmol), aniline (0.1118 g, 1.20 mmol) were placed in a 50 ml flask, after a few drops of acetic acid were added in, the mixture was subjected to radiation in a 800 W microwave oven for 2 min and 3 min on a medium-heat setting. The reaction was monitored by TLC, and the crude product was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate, 5:1 v/v), the colourless or light yellow crystals of the title compound were at last obtained by recrystallization from ethanol (yield 0.063 g, 28.4% Plate like colourless single crystals used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation of the solvent at room temperature.

Refinement
All H atoms were placed at calculated positions and refined as riding, with C-H = 0.93-0.96Å, N-H = 0.86Å, and with U iso (H) = 1.2U eq (C, N) and U iso (H) = 1.5U eq (C) for methyl H atoms.

Computing details
Data collection: APEX2 (Bruker,2008); cell refinement: SAINT (Bruker,2008); data reduction: SAINT (Bruker,2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).   where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.20 e Å −3 Δρ min = −0.13 e Å −3 Extinction correction: SHELXL97 (Sheldrick, 2008), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.043 (5) Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.