Adding some certain compound to certain chemical reactions, such as: 71838-16-9, name is 2-Bromo-1-iodo-4-methylbenzene, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 71838-16-9. 71838-16-9
General procedure: Et2NH (20 mL), THF (20 mL), 1-bromo-2-iodobenzene (2.2 mL g,18 mmol), and trimethylsilylacetylene (2.9 mL, 21 mmol) weresuccessively added to a flask containing PdCl2(PPh3)2 (0.25 g,0.35 mmol) and CuI (0.067 g, 0.35 mmol). The mixture was stirredat room temperature for 12 h and then evaporated. The residuewasdiluted with hexane/AcOEt (5:1) and washed with 1M aqueousHCl. The organic layer was dried over Na2SO4 and evaporated. Purificationof the residue by silica-gel column (hexane) gave 1-bromo-2-[2-(trimethylsilyl)ethynyl]benzene [38274-16-7] (1a?) asa pale yellow clear liquid (4.12 g, 16.3 mmol, 92% yield).nBuLi (2.65M in hexane, 701 mL, 1.86 mmol) was added to astirred solution of 1a? (472 mg, 1.86 mmol) in THF (4 mL) at 78 C.After 0.5 h, Me2SiCl2 (223 mL, 1.86 mmol) was added to the mixtureat that temperature. Then the mixture was warmed to room temperatureand stirred for 2 h. MeOH (0.5 mL) and Et3N (290 mL,2.08 mmol) were successively added to the reaction mixtureat 78 C. After removing the cooling bath, the resultant mixturewas stirred at room temperature for 1 h. The mixturewas quenchedwith water and extracted with hexane/AcOEt (30:1) three times.The combined organic layer was dried over Na2SO4 and evaporated.The residuewas purified by flash column chromatography (hexane/AcOEt 40:1). The title compound,1-(methoxydimethylsilyl)-2-[2-(trimethylsilyl)ethynyl]benzene (1a), was obtained as a pale yellowliquid (0.721 g, 2.75 mmol, 71% yield). 1H NMR (500 MHz, CDCl3,7.26 ppm) d 0.25 (s, 9H), 0.47 (s, 6H), 3.56 (s, 3H), 7.30e7.34 (m, 2H),7.48e7.50 (m, 1H), 7.59e7.61 (m, 1H); 13C NMR (125 MHz, CDCl3,77.0 ppm) d 1.8, 0.3, 50.9, 96.9, 106.4, 127.7, 127.7, 129.2, 132.8,134.0, 140.8; IR (neat) 3073, 3052, 2959, 2831, 2155, 1429 cm1;HRMS (EI) calcd for C14H22OSi2 [M] 262.1209, found 262.1209.The substrates 1b-l, and 1p were synthesized by the samemanner as described for the preparation of 1a.
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 2-Bromo-1-iodo-4-methylbenzene.
Reference:
Article; Kinoshita, Hidenori; Fukumoto, Hiroki; Ueda, Akihiro; Miura, Katsukiyo; Tetrahedron; vol. 74; 14; (2018); p. 1632 – 1645;,
Iodide – Wikipedia,
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