9,10-Dioxoanthracene-1,4-diyl bis(4-methylbenzenesulfonate)

The title molecule, C28H20O8S2, has a T-shaped conformation. The central 9,10-anthraquinone moiety is bow-shaped with the two outer aromatic rings being inclined to one another by 13.99 (11)°. The benzenesulfonate rings are inclined to one another by 47.35 (12)°, and by 34.51 (11) and 17.88 (11)° to the bridging aromatic ring of the 9,10-anthraquinone moiety. In the crystal, C—H⋯O interactions link the molecules into ribbons in [100].

The title molecule, C 28 H 20 O 8 S 2 , has a T-shaped conformation. The central 9,10-anthraquinone moiety is bow-shaped with the two outer aromatic rings being inclined to one another by 13.99 (11) . The benzenesulfonate rings are inclined to one another by 47.35 (12) , and by 34.51 (11) and 17.88 (11) to the bridging aromatic ring of the 9,10-anthraquinone moiety. In the crystal, C-HÁ Á ÁO interactions link the molecules into ribbons in [100].
1,4-Bis(hydroxy)anthraquinone is one of an important anthraquinone starting materials for preparation the various anthraquinone dyes and pigments (Zielske, 1987). In this work, we report the intermediate of an anthraquinone dye with the two symmetric tosylate substituents.
The molecular structure of 1,4-bis(tosyloxy)anthraquinone consisting of the two tosylate groups substituted at 1,4positions of anthraquinone core, has a dragonfly-like conformation with the stranded 9,10-anthraquinone fragment. The anthraquinone plane is distorted by 0.1814 Å from the mean plane defined by 16 atoms becuase of the steric effect of two substitued tosyl groups. The O1 and O2 atoms were deviatated from the anthraquinone mean plane with the distances of -0.2736 (16) Å and -0.1467 (15) Å, respectively, which are respectively in the normal range for the distortion of oxyquinone reported for 1,4-bis(hydroxy)anthraquinone (Swaminathan et al., 1967). Additionally, the moderate intermolecular hydrogen bonds of sp 2 C-H···O have been investigated between the hydrogen atom bound the aromatic carbon inside quinone ring, and the oxygen atom at the sulfonate group in the p-toluenesulfonate moiety as Figure  Experimental 1,4-Bis(tosyloxy)anthraquinone was prepared by a stirred solution of 1,4-bis(hydroxyl)anthraquinone or quinizarin (0.241 g, 1.00 mmol) in 25 mL of dry dichloromethane was added triethylamine (0.205 g, 2.03 mmol) and p-toluenesulfonyl chloride (0.383 g, 2.01 mmol). The solution was stirred at room temperature for 24 hours. The precipitate was filtered off and then washed with water and dried over magnesium sulfate. Filtration of slurry gave a bright yellow-green solid. The final product was recrystallized in hexane:dichloromethane using slow evaporation which was suitable for X-ray diffraction analysis. Additionally, 1 H of 1,4-bis(tosyloxy)anthraquinone were recorded in CDCl 3 solution on a Varian Mercury Plus 400 spectrometer. 1 H NMR spectrum (δ, ppm): 7.94-8.02 (2H,m); 7.69-7.91 (6H,m); 7.45 (2H,s); 7.24-7.33 (4H,m); 2.35 (6H,s) (Zielske et al., 1987).

Figure 1
The molecular structure of the title compound showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

9,10-Dioxoanthracene-1,4-diyl bis(4-methylbenzenesulfonate)
Crystal data  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.