Electric Literature of 2620-76-0,Some common heterocyclic compound, 2620-76-0, name is 2-(4-Bromophenyl)-1-phenyl-1H-benzoimidazole, molecular formula is C19H13BrN2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
[Example 4] This example will give descriptions of a method of synthesizing 2-[4-(6-phenyldibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: DBTBIm-IV) represented by the following Structural formula (188). [Show Image] [Synthesis of 2-[4-(6-phenyldibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: DBTBIm-IV)] The synthesis scheme of 2-[4-(6-phenyldibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: DBTBIm-IV) is illustrated in (B-4). [Show Image] In a 100-mL three-neck flask, a mixture of 1.7 g (5.0 mmol) of 2-(4-bromophenyl)-1-phenyl-1H-benzimidazole, 1.5 g (5.0 mmol) of 6-phenyldibenzothiophen-4-boronic acid, 22 mg (0.1 mmol) of palladium(II) acetate, 60 mg (0.2 mmol) of tri(ortho-tolyl)phosphine, 20 mL of toluene, 2 mL of ethanol, and 7.5 mL of a 2 mol/L aqueous solution of potassium carbonate was stirred to be degassed under reduced pressure. Then, the mixture was heated and stirred at 90 °C for 2.5 hours under a nitrogen stream. After a predetermined time, 150 mL of toluene was added to this mixture solution, and the organic layer of the resulting suspension was suction filtered through Celite (produced by Wako Pure Chemical Industries, Ltd., Catalog No. 531-16855). The resulting filtrate was concentrated, followed by purification using silica gel column chromatography. The silica gel column chromatography was carried out using a mixed solvent of toluene and ethyl acetate in a ratio of 19 to 1 as a developing solvent. The obtained fractions were concentrated, and acetone and methanol were added to the mixture, followed by irradiation with ultrasonic waves. The precipitated solid was collected by suction filtration. Thus, 2.2 g of a white powder was obtained in 83percent yield, which was the substance to be produced. The Rf values of the produced substance and 2-(4-bromophenyl)-1-phenyl-1H-benzimidazole were respectively 0.21 and 0.36, which were found by silica gel thin layer chromatography (TLC) (with a developing solvent containing ethyl acetate and hexane in a ratio of 1 to 5). The nuclear magnetic resonance (NMR) measurement identified this compound as 2-[4-(6-phenyldibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: DBTBIm-IV). 1H NMR data of the obtained compound are as follows: 1H NMR (CDCl3, 300 MHz): delta (ppm) = 7.26-7.59 (m, 15H), 7.64-7.71 (m, 6H), 7.90-7.93 (d, J = 7.8 Hz, 1H), 8.15-8.19 (m, 2H). FIGS. 18A and 18B illustrate the 1H NMR charts. Note that FIG. 18B is a chart showing an enlarged part of FIG. 18A in the range of 7.0 ppm to 8.5 ppm. Further, FIG. 19A shows an absorption spectrum of a toluene solution of DBTBIm-IV, and FIG. 19B shows an emission spectrum thereof. FIG. 20A shows an absorption spectrum of a thin film of DBTBIm-IV, and FIG. 20B shows an emission spectrum thereof. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V-550, produced by JASCO Corporation). The measurements were performed with samples prepared in such a manner that the solution was put in a quartz cell while the thin film was obtained by evaporation onto a quartz substrate. The absorption spectrum of the solution was obtained by subtracting the absorption spectra of quartz and toluene from those of quartz and the solution, and the absorption spectrum of the thin film was obtained by subtracting the absorption spectrum of a quartz substrate from those of the quartz substrate and the thin film. In FIGS. 19A and 19B and FIGS. 20A and 20B, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). In the case of the toluene solution, an absorption peak was observed at around 316 nm and emission wavelength peaks were 371 nm and 387 nm (excitation wavelength: 320 nm). In the case of the thin film, absorption peaks were observed at around 242 nm, 304 nm, and 319 nm, and an emission wavelength peak was 402 nm (excitation wavelength: 349 nm).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-(4-Bromophenyl)-1-phenyl-1H-benzoimidazole, its application will become more common.
Reference:
Patent; SEMICONDUCTOR ENERGY LABORATORY CO., LTD.; EP2354135; (2011); A1;,
Imidazole – Wikipedia,
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