2-{Hydroxy[1-(4-methoxyphenyl)-4-oxo-3-phenylazetidin-2-yl]methyl}acrylonitrile

In the title compound, C20H18N2O3, the β-lactam ring is essentially planar, having a maximum deviation of 0.0291 (15) Å for the N atom, and perpendicular to the phenyl ring [dihedral angle = 85.55 (11)°]. The carbonitrile side chain is almost linear, the C—C—N angle being 176.8 (2)°. The crystal packing is stabilized by intermolecular O—H⋯O and C—H⋯O interactions.

In the title compound, C 20 H 18 N 2 O 3 , the -lactam ring is essentially planar, having a maximum deviation of 0.0291 (15) Å for the N atom, and perpendicular to the phenyl ring [dihedral angle = 85.55 (11) ]. The carbonitrile side chain is almost linear, the C-C-N angle being 176.8 (2) . The crystal packing is stabilized by intermolecular O-HÁ Á ÁO and C-HÁ Á ÁO interactions.

Comment
Acrylonitriles are useful intermediates in organic synthesis and are capable of undergoing many useful organic transformations (Ambrosi et al., 1994), for example, into pyrazole, isoxazole and pyrimidine derivatives. β-Lactams are one of the best known and most extensively studied class of compounds due to their biological activities. The most commonly used β-lactam antibiotics for the therapy of infectious diseases are penicillin and cephalosporin (Brakhage, 1998). X-ray analysis confirms the molecular structure and atom connectivity as illustrated in Fig. 1.
In the title compound C 20 H 18 N 2 O 3 , due to conjugation in the C19═C18-C20≡N2 moiety, the bond length between C18 and C20 (1.429 (3)Å) shows a significant shortening (Nizam Mohideen et al., 2007). The β-lactam ring is essentially planar and the keto O1 atom deviates from this mean plane by -0.1095 (13)°. The methoxy phenyl (C11-C15) and the phenyl rings (C1-C6) form dihedral angles of 15.66 (10)° and 85.55 (11)°, respectively, with the β-lactam ring. The sum of the angles around N1 atom of the β-lactam ring system accounts for 359.5 (3)° which is in accordance with sp 2 hybridization. The phenyl ring and methoxy phenyl ring are cis related with respect to the β-lactam ring.
The bond angles at C18 deviate significantly from regular trigonal geometry. The bond angle around C20, in the chains of atoms C18/C20/N2, is 176.8 (2)° and thus the carbonitrile side chain is almost linear. The torsion angle of -112.87 (19)°f or C7-C17-C18═C19 indicates a deviation of the β-lactam ring from the plane of the olefinic double bond. The methoxy group is slightly twisted from the plane of the phenyl ring (C10-C15) to which it is attached as evidenced by the torsion angle C14-C13-O2-C16 of 7.8 (2)°. The interplanar angle between the phenyl (C1-C6) and methoxy phenyl group (C10-C15) is 81.04 (9)°. The title compound exhibits structural similarities with the already reported related structures (Sundaresan et al., 2008, Kamala et al., 2008. The crystal packing is stabilized by O-H···O and C-H···O hydrogen bonds via O3-H3···O1 i and C9-H9···O2 ii intermolecular interactions, viewed down the a axis. Symmetry codes: (i) x, -y, z+1/2; (ii) x+1, y, z. The packing view of the title compound is shown in Fig. 2.

Experimental
To the reaction mixture of 1-(4-methoxyphenyl)-4-oxo-3-phenylazetidine-2-carbaldehyde (1 mmol) with acrylonitrile (2 mmol), a catalytic quantity of 1,4-diazabicyclo[2.2.2]octane (10-15 mol %) was added. The reaction mixture was left standing at room temperature in a stoppered sample flask. The progress of the reaction was monitored by TLC over a period of several days. After a period of 10 days, the TLC revealed the presence of a product. The reaction mixture was dissolved in ethyl acetate and washed with aqueous HCl solution (0.25 M) and water followed by brine solution. The organic layer was separated and dried over sodium sulfate. Filtering and evaporation of the organic solvent was done under reduced pressure.
The product was separated by flash column chromatography using hexane and ethyl acetate as an eluent (1:9) to give colourless solid. The product was dissolved in chloroform and heated for two minutes. The resulting solution was subjected to crystallization by slow evaporation of the solvent resulting in single crystals suitable for XRD studies.

Refinement
The hydrogen atoms were placed in calculated positions with C-H = 0.93Å to 0.98Å, O-H = 0.82Å and refined in the riding model with fixed isotropic displacement parameters: U iso (H) = 1.2U eq (C) for aromatic, methylene, methine groups, U iso (H) = 1.5U eq (C) for methyl group and U iso (H) = 1.5U eq (O) for hydroxy groups.