4,4'-DIBROMO-TRANS-STILBENE

Next, 50.2 g (97.9 mmol) of (4-bromobenzyl)triphenylphosphoniumbromide, which is obtained above, and 21.7 g (118 mmol) of 4-bromobenzaldehyde were put into a 500 mL three-neck flask, and then the air in the flask was replaced with nitrogen. Then, 200 mL of tetrahydrofuran (THF) was added thereto. Then, a suspension in which 13.2 g (118 mmol) of potassium tert-butoxide was dissolved in 100 mL of THF was dropped to this mixture. After the dropping, the reaction mixture was stirred for 24 hours at room temperature. After the reaction, water was added to the reaction mixture, and a precipitate was collected by suction filtration to give 14.0 g of a white powdered solid of (E)-4-4'-dibromostilbene (yield: 42.1%). Further, it is possible to obtain (Z)-4, 4'dibromostilbene by the following method. From the filtrate which is obtained by the foregoing suction filtration, a product was extracted with ethyl acetate. The obtained extraction solution was dried with magnesium sulfate. Then, the mixture was suction filtrated, and the filtrate was concentrated. The obtained residue was purified by silica gel column chromatography (developing solution: toluene). Then, the obtained solution was concentrated to give 14.8 g of a light yellow solid of (Z)-4, 4'dibromostilbene (yield: 45%). A synthesis scheme (f-2) of 4, 4'dibromostilbene is shown below. Note that (E)-4-4'-dibromostilbene is used in this embodiment.(ii) Synthesis of 4, 4'-dibromostilbene 50.2 g (97.9 mmol) of 4-bromobenzyltriphenylphosphonium bromide and 21.7 g (118 mmol) of 4-bromobenzaldehyde were put into a 500 mL three-necked flask. Then, the atmosphere in the flask was substituted with nitrogen. Thereafter, 200 mL of tetrahydrofuran (abbreviation: THF) was added to the mixture. A suspension obtained by mixing 13.2 g (118 mmol) of potassium-tert-butoxide into 100 mL of THF was dropped to this mixture. Thereafter, the mixture was stirred at room temperature for 24 hours to be reacted. After the reaction, the reaction solution was washed with water, and then a precipitate was collected by suction filtration. Then, 14.0 g of objective (E)-4, 4'-dibromostilbene was obtained as a white powdered solid in a yield of 42%. Further, the filtrate from which the precipitate was collected was extracted with ethylacetate and the extracted solution was dried over magnesium sulfate. After the drying, the mixture was subjected to suction filtration and the filtrate was condensed. The obtained residue was purified by silica gel column chromatography (developing solution: toluene). The obtained solution was condensed; then 14.8 g of (Z)-4, 4'-dibromostilbene was obtained as a light yellow solid in a yield of 45%. Synthetic scheme of 4, 4'-dibromostilbene is illustrated below (synthetic scheme a-2).Preparing Example 3 Preparation Of (E)-1, 2-Bis(P-Phenyl-Bromide)Ethene) (Compound B) Potassium tert-butoxide (4.08 g, 36.4 mmol) was in a one-neck bottle. After introducing nitrogen gas by vacuum pumping, anhydrous tetrahydrofuran (25.0 mL) was added. Then, compound A (6.30 g, 20.0 mmol) and 4-bromobenzaldehyde (3.37 g, 18.2 mmol) were in another two-neck bottle. After introducing nitrogen gas by vacuum pumping, anhydrous tetrahydrofuran (25.0 mL) was added. The said potassium tert-butoxide and solution was added slowly under ice bath for 30 minutes. After the reaction finished and was back to room temperature, the organic layer was exacted with ethyl acetate and water respectively and collected, then removing water with magnesium sulphate and condensing. After column chromatography with n-hexane, white solids of 6.09 g with a yield of 99% were obtained. 1H NMR (400 MHz, CDCl3, delta): 7.46 (d, J=8.4 Hz, 2H), 7.34 (d, J=8.4 Hz, 2H), 7.00 (s, 1H). 13C NMR (100 MHz, CDCl3, delta): 135.9, 131.8, 128.1, 128.0, 121.6.2.1.2 (E)-1, 2-Bis(4-bromophenyl)ethane (2) A mixture of (4-bromobenzyl)phosphonic acid diethyl ester (2.71 g, 11.0 mmol) and potassium tert-butoxide (3.37 g, 30.0 mmol) in THF (20 mL) was stirred in an ice-water bath for several minutes and then 4-bromobenzaldehyde (1.85 g, 10.0 mmol) was added. The solution was maintained at 0 C and stirred continuously for a further 5 h. Then, the reaction was quenched through the addition of ice water. The mixture was partitioned between DCM and water and then the organic phase was collected, dried (MgSO4), filtered, and evaporated to dryness. The residue was recrystallized (MeOH/THF) to provide a white solid (2.43 g, 72%). 1H NMR (400 MHz, CDCl3) delta (ppm): 7.09 (s, J = 7.4 Hz, 2 H), 7.24 (d, J = 7.4 Hz, 4 H), 7.45 (d, 4 H). EIMS (m/z): calcd for C14H10Br2, 338.3; found: 338.1. Anal. Calcd for C14H10Br2: C, 44.20; H 2.96. Found: C, 44.32; H, 2.975.

Molecular Weight:338.04
XLogP3:5.6
Rotatable Bond Count:2
Exact Mass:337.91288
Monoisotopic Mass:335.91493
Heavy Atom Count:16
Complexity:197
Defined Bond Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes