* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With N-Bromosuccinimide; dibenzoyl peroxide In tetrachloromethane at 85℃; for 18 h; Inert atmosphere
To a stirred solution of 3-bromo-4-methyl-benzonitrile (2 g, 10.2014 mmol, 100 mass percent) in carbon tetrachloride (20 ml_, 100 mass percent) under argon, was added NBS (2.2 g., 12.2417 mmol, 99 mass percent) and benzoyl peroxide (0.123 g., 0.5101 mmol, 100 mass percent). The mixture was heated to 85°C for 18h. The reaction mass was diluted with water (50 ml) and extracted with ethyl acetate. Organics were washed again with water and brine, dried and evaporated to afford 3-bromo-4-(bromomethyl) benzonitrile (1.2 g, 4.4 mmol, 90 mass percent, 95percent Yield) as an off white solid solid. H NMR (400 MHz, chloroform-c) δ ppm 3.89 - 4.01 (m, 2 H) 6.61 - 6.77 (m, 1 H) 6.92 - 7.07 (m, 2 H) LCMS: RT 1.12-1.49 Min 274 [M+H] +
52.5%
With N-Bromosuccinimide; dibenzoyl peroxide In tetrachloromethaneInert atmosphere; Reflux
The compound 57 (804 mg, 4.04 mmol) was dissolved in carbon tetrachloride (8 mL), and then added with NBS (730 mg, 4.10 mmol) and benzoyl peroxide (7 mg, 0.0289 mmol). The resulting mixture was heated under the protection of nitrogen until reflux occurred, and was stirred overnight. The mixture was cooled to room temperature, filtered to remove insoluble substances and distilled under reduced pressure to remove the solvent, then dissolved in ethyl acetate (30 mL) and respectively washed with water (10 mL) and saturated saline solution (10 mL). After the solvent was removed by means of reduced pressure distillation, the resulting product was purified by using a silica column (200 to 300 mesh silica gel, ethyl acetate/petroleum ether=1/35 for elution) to obtain 3-bromo-4-cyanobenzyl bromide (58) (583 mg), with a yield of 52.5percent.
Reference:
[1] Patent: WO2016/113303, 2016, A1, . Location in patent: Page/Page column 41
[2] Journal of the American Chemical Society, 2017, vol. 139, # 2, p. 829 - 835
[3] Journal of the American Chemical Society, 2009, vol. 131, # 39, p. 13908 - 13909
[4] Patent: EP2927219, 2015, A1, . Location in patent: Paragraph 0130; 0132
[5] Journal of Organic Chemistry, 1964, vol. 29, p. 2034 - 2036
[6] Bioorganic and Medicinal Chemistry Letters, 2003, vol. 13, # 21, p. 3821 - 3825
[7] Patent: WO2010/85581, 2010, A1, . Location in patent: Page/Page column 71-72
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[9] Patent: WO2011/22337, 2011, A1, . Location in patent: Page/Page column 104
2
[ 42872-74-2 ]
[ 956218-04-5 ]
Reference:
[1] Synlett, 2007, # 14, p. 2179 - 2184
Step 1 : Synthesis of 5-cyano-2-methylphenylboronic acid First, 9.5 g (50 mmol) of <strong>[42872-74-2]3-bromo-4-methylbenzonitrile</strong> was put into a 500 mL three-neck flask, and the atmosphere in the flask was replaced with nitrogen. Then, 250 mL of tetrahydrofuran (THF) was added, and the mixture was stirred at -78 C for 30 minutes. Into this mixed solution, 34 mL (55 mmol) of a 1.63M hexane solution of -butyllithium (-BuLi) was dropped, followed by stirring at -78 C for 1.5 hours. After that, 7.3 mL (65 mmol) of trimethyl borate was added to the mixture and this solution was stirred for 20 hours while the temperature was raised to room temperature. To this solution was added 100 mL of 1M hydrochloric acid and stirring was performed for 30 minutes. The obtained mixture was separated to an aqueous layer and an organic layer, and the aqueous layer was subjected to extraction with ethyl acetate. The organic layer and a solution of the extract were combined, and washed with saturated saline. Anhydrous magnesium sulfate was added to the obtained solution for drying. The obtained mixture was subjected to gravity filtration, and the filtrate was concentrated to give a solid. This solid was washed with toluene and hexane, so that 4.3 g of a white solid was obtained in a yield of 53 %. The obtained white solid was identified as 5-cyano-2-methylphenylboronic acid by nuclear magnetic resonance ( MR) spectroscopy. The synthesis scheme of Step 1 is shown in (a-10) below.