4-(Benzyloxy)benzaldehyde

The title compound, C14H12O2, has an essentially planar conformation with the two aromatic rings forming a dihedral angle of 5.23 (9)° and the aldehyde group lying in the plane of its aromatic group [maximum deviation = 0.204 (3) Å]. Weak intermolecular C—H⋯O contacts are found to be shortest between the aldehyde O-atom acceptor and the H atoms of the methylene group.

The title compound, C 14 H 12 O 2 , has an essentially planar conformation with the two aromatic rings forming a dihedral angle of 5.23 (9) and the aldehyde group lying in the plane of its aromatic group [maximum deviation = 0.204 (3) Å ]. Weak intermolecular C-HÁ Á ÁO contacts are found to be shortest between the aldehyde O-atom acceptor and the H atoms of the methylene group.
MOO thanks the Commonwealth Scholarship Commission and the British Council for funding and Moi University for sabatical leave.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GW2083).  (Jones et al., 2006). The effectiveness of the drugs that have already been developed is thus affected by the emergence of drug resistant strains. Consequently, NNRTIs having a good activity against wild-type RT and the most prevalent mutant viral strains are needed. There is therefore the need to look for new compounds that are highly potent and less susceptible to mutations of RT-enzyme (Christer et al., 1998). According to Himmel et al. (2006), new lead compounds that target novel binding sites are needed because of rapid emergence of these drug resistant variants of HIV-1 which has limited the efficacy of AIDS treatment. This study was therefore limited to the use of Wiener's topological index, a theoretical approach used in theoretical chemistry to predict the anti-HIV activity of phenylethylthiazolylthiourea (PETT) analogues.

Structure Reports Online
The title compound, 4-(benzyloxy)benzaldehyde, was an intermediate in the production of such target compounds. It was found to exist as discrete molecules (Figure 1), although there are some non-classical hydrogen bonding C-H···O interactions involving the aldehyde O atom and both the methylene H atoms (H···O 2.50 and 2.53 Å) and aromatic H atoms (2.69 and 2.80 Å). Similar interactions are described for the similar 2-methoxy vanillin derivitive by Gerkin (1999). All contacts to the ether O atom are longer than these.
Bond lengths are similar to those found in the structures of related compounds and the aldehyde is coplanar with the ring in all cases (here C10C11C14O2 = -6.3 (3) °. However, two different conformations are found for these compounds.

Experimental
All reactions in the preparation of 4-(benzyloxy)benzaldehyde were performed under an atmosphere of nitrogen gas. 5.0 g of 4-hydroxybenzaldehyde (40.98 mmol), 5.0 ml of benzylbromide (42.05 mmol) and 20.0 g of anhydrous potassium carbonate (144.27 mmol) in ethanol were refluxed for 14 hours. Potassium carbonate was filtered out and large volumes of EtOAc were used to wash the residue. Rotavapour apparatus was used to remove the solvent. The residual mass was dissolved in 50 ml Et 2 O. Two portions of 50 mL saturated sodium chloride solution were used to wash the Et 2 O solution.
Thereafter, it was washed with one portion of 5% sodium hydroxide solution. Finally, the Et 2 O solution was washed with distilled water. Anhydrous magnesium sulphate was used to dry the Et 2 O solution and the solvent removed under reduced pressure. The crude product was then recrystallized from ethanol to give colorless crystals (7.58 g, 87.4%). Mp: 338-339 K.

Refinement
The aldehyde H atom (H14) was refined freely, but all other atoms were placed in calculated positions and refined in riding modes with U iso (H) = 1.2U eq (C). C-H distances 0.95 and 0.99 Å for CH and CH 2 respectively. Fig. 1. The molecular structure showing 50% probability displacement ellipsoids.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 Rfactors(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.