3-(2,3-Dimethoxyphenyl)-2,3-dihydro-1H-benzo[f]chromen-1-one

The crystal structure of a flavanone is reported in which C—H⋯O hydrogen bonds link the molecules into chains.


Structure description
Flavanones exhibit a wide range of biological properties, including antiviral (Shi et al., 2022), antifungal (Emami et al. 2013) and anticancer activities (Bailly, 2021;Zhao et al., 2019) as well as being used in the treatment of Alzheimer's disease (Jin et al., 2021). In continuation of our research into flavanone derivatives (Sung, 2020), the title compound was synthesized and its crystal structure was determined.

Synthesis and crystallization
A solution of 2-hydroxy-1-acetonaphthone (186 mg, 1 mmol) and 2,3-dimethoxybenzaldehyde (166 mg, 1 mmol) was dissolved in ethanol (15 ml) and the temperature was adjusted to around 276-277 K in an ice bath. To the cooled reaction mixture was added 1.0 ml of 40% aqueous KOH solution, and the reaction mixture was stirred at room temperature for 24 h. This mixture was poured into iced water (50 ml) acidified with 6 N HCl solution. The mixture was extracted with ethyl acetate (3 Â 30 ml) and the combined organic layers were dried under MgSO 4 . Filtration and evaporation of the filtrate gave a solid chalcone, which was dissolved in DMSO and a catalytic amount of conc. HCl was added. After 10 h, the reaction mixture was poured into iced water to give a solid flavanone. Recrystallization from ethanol solution gave the crystals used in this X-ray diffraction study.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2.

Figure 1
The molecular structure of the title compound, showing the atomlabelling scheme and displacement ellipsoids drawn at the 50% probability level.

data-1
IUCrData ( where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.30 e Å −3 Δρ min = −0.38 e Å −3 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.

data-2
IUCrData (2022). 7, x220885 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.