In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 3975-77-7, name is 2-Bromo-1,3,5-tri-tert-butylbenzene belongs to bromides-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below. Recommanded Product: 2-Bromo-1,3,5-tri-tert-butylbenzene
A solution of bromo-2,4,6-tri-tert-butylbenzene (?supermesityl bromide, Mes*Br?, 326mg, 1.00mmol) in pentane (1.5mL) and THF (0.7mL) was cooled to-60C under argon gas cover for the injection of nBuLi (1.13mmol) in hexane (0.50mL). After one hour at rt, the supernatant was withdrawn from the precipitated 2,4,6-tri-tert-butylphenyllithium (Mes*Li), which was then washed with dry pentane (2×1mL). The subsequent addition of anhydrous Et2O (0.6mL) dissolved Mes*Li partially, and the entailing treatment with 2,2,6,6-tetramethylpiperidine (HTMP, 0.034mL, 28mg, 0.2mmol) consumed a corresponding portion of Mes*Li. The mixture was treated with the enone 10 (80mg, 0.30mmol) and kept at-60C for 1h, whereafter Mes*Li had been dissolved entirely. The solution was transferred to an NMR tube (5mm) and observed until 10 (deltaH=6.54ppm) had vanished (24h). The tube should be cooled in ice during the final addition of D2O (0.10mL). The resultant mixture was diluted with aqueous HCl (2M, 2mL) and Et2O (5mL). The acidic aqueous layer was shaken with Et2O (2×5mL) and discarded. The combined Et2O phases were washed with distilled water (3×3mL), dried over Na2SO4, filtered, and concentrated to leave a mixture (108mg) of 19, Mes*H, and partially (81%) deuteriated enone 10 in a 10:68:22M ratio. Analytically pure 19 had mp 202-203C (from 10mL of ethanol). (0032) IR (KBr) nu 3566 (very sharp O-H), 2961, 2870, 1595, 1485, 1474, 1458, 1362, 754cm-1. (0033) 1H NMR (CDCl3, 400MHz) delta 0.94 (s, 9H, 3×Me-1?), 1.04 (d, 4J=1.2Hz, 1H, OH), 1.25 (s, 3H, 5?-Mea), 1.31 (s, 18H, 2×meta-CMe3), 1.35 (s, 3H, 3-Mea), 1.40 (s, 3H, 3-Meb), 1.43 (s, 3H, 1-Mea), 1.49 (s, 3H, 1-Meb), 1.52 (s, 3H, 5?-Meb), 1.90 (d, 2J=15.2Hz, 1H, 4?-Ha), 2.70 (d, 2J=15.2Hz, 1H, 4?-Hb), 5.40 (d, 4J=1.2Hz, 1H, alpha-H), 7.12 (m, 1H, 4-H), 7.14 (m, 1H, 7-H), 7.18 and 7.19 (2m, 2H, 5-/6-H), 7.24 (d, 4J=1.7Hz, 2H, 2×ortho-H), 7.28ppm (t, 4J=1.7Hz, 1H, para-H), assigned through the NOESY correlations 3-Mea+b ? alpha-H ? 4?-Ha ? 4?-Hb ? ortho-H ? meta-C(CH3)3 ? para-H; 1-Mea ? 1-Meb ? HO ? ortho-H; 5?-Mea ? ortho-H ? 5?-Meb ? HO ? 1-Meb ? meta-C(CH3)3; (0034) 13C NMR (CDCl3, 100.6MHz) delta 26.3 (qsept, 1J=125.5Hz, 3J=4.9Hz, 3×Me-1?), 26.7 (qm, 1J=ca. 124 Hz, 5?-Meb), 31.2 (qm, 1J=124.5Hz, 1-Mea), 31.5 (qsept, 1J=125Hz, 3J=4.9Hz, 2×meta-CMe3), 32.30 and 32.32 (2 qm, 1J=126Hz, 1-Meb and 3-Meb), 33.2 (qm, 1J=126Hz, 3-Mea), 35.0 (quat, 2×meta-CMe3), 37.2 (qm, 1J=126.0Hz, 5?-Mea), 37.8 (quat, C-5?), 40.5 (quat, C-2?), 46.3 (quat, C-1), 48.7 (tm, 1J=124Hz, CH2-4?), 49.3 (quat, C-3), 81.3 (quat, C-3?), 120.0 (dt, 1J=153Hz, 3J=6.5Hz, C-para), 120.3 (dt, 1J=152Hz, 3J=6.5Hz, 2×C-ortho), 122.3 (dd, 1J=156Hz, C-7), 122.6 (dd, 1J=156Hz, C-4), 126.3 (dd, 1J=158Hz, 3J=7.4Hz, C-5), 126.8 (dd, 1J=158Hz, 3J=7.4Hz, C-6), 128.6 (dm, 1J=140.6Hz, C-alpha), 147.1 (quat, C-3a), 148.0 (quat, C-7a), 150.6 (sept, 3J=3.7Hz, 2×C-meta), 152.1 (quat, C-ipso), 154.1ppm (quat, C-2), assigned through the coupling constants, comparison with 13b, and the selective {1H} decoupling experiment {CH2 and all CH3} ? C-1 as a d with 3J=8Hz (trans to alpha-H), C-2 as a d with 2J=3.8Hz to alpha-H, C-ipso as a t with 3J=ca. 6 Hz, C-meta as a. Anal. calcd for C37H56O (516.9): C, 85.98; H, 10.92. Found: C, 85.93; H, 10.83.
The synthetic route of 3975-77-7 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Knorr, Rudolf; Schmidt, Barbara; Freudenreich, Johannes; von Roman, Therese; Tetrahedron; vol. 74; 52; (2018); p. 7466 – 7471;,
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