3-Bromo-4-dibenzylamino-5-methoxyfuran-2(5H)-one

In the the title compound, C19H18BrNO3, the furanone ring is almost planar [maximum atomic deviation = 0.019 (3) Å] and is nearly perpendicular to the two phenyl rings, making dihedral angles of 88.96 (17) and 87.71 (17)°. Intermolecular C—H⋯O hydrogen bonding is present in the crystal structure.

In the the title compound, C 19 H 18 BrNO 3 , the furanone ring is almost planar [maximum atomic deviation = 0.019 (3) Å ] and is nearly perpendicular to the two phenyl rings, making dihedral angles of 88.96 (17) and 87.71 (17) . Intermolecular C-HÁ Á ÁO hydrogen bonding is present in the crystal structure.
The structure of the title compound (I) is illustrated in Fig. 1. The title compound contains a five-membered furanone ring and two six-membered benzene rings. The furanone ring is approximately planar.
After the mixture of dibenzylamine (2 mmol) and potassium fluoride (6 mmol) was dissolved in absolute tetrahydrofuran (2 ml) under nitrogen atmosphere, dichloromethane solution of 3,4-dibromo-5-methoxyfuran-2(5H)-furanone (2.0 mmol) was added. The residual liquid was dissolved in dichloromethane. The reaction was carried out under the stirring at room temperature for 48 h. Once the reaction was complete, the solvents were removed under reduced pressure. The residual solid was dissolved in dichloromethane. Then the combined organic layers from extraction were concentrated under reduced pressure, and the crude product was purified by silica gel column chromatography with the gradient mixture of petroleum ether and ethyl acetate to give the product yielding (I) 0.6224 g (80.2%).

Refinement
H atoms were positioned in calculated positions with C-H = 0.93-0.98 Å and were refined using a riding model, with U iso (H) = 1.5U eq (C) for methyl and 1.2U eq (C) for the others. 3-Bromo-4-dibenzylamino-5-methoxyfuran-2(5H)-one 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 > 2sigma(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.