Electric Literature of 69038-74-0, These common heterocyclic compound, 69038-74-0, name is tert-Butyl 3-Bromobenzoate, its 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.
(+)-Pinanediol 3-(teri-butoxycarbonyl)benzeneboronate (12b). A solution of tert- butyl 3-bromo-benzoate (1.70 g, 6.61 mmol), obtained from 3-bromobenzoic acid, (Wright, S. W. et al, Tetrahedron Lett. 1997, 38, 7345-7348) and freshly distilled triisopropyl borate (1.53 mL, 6.61 mmol) in THF (17 mL) was cooled to -100 °C under argon flow and w-butyllithium (2.5 M soln in hexane, 2.91 mL, 7.27 mmol) was added dropwise over 15 min, during which the solution turned cherry red. After 1 h at -100 °C, trimethylsilyl chloride (0.84 mL, 6.61 mmol) was dropped into the reactor and the resulting colorless solution was allowed to warm to room temperature and stirred overnight. Finally, (+)-pinanediol (1.12 g, 6.61 mmol) was added and the solution stirred 1 h at room temperature. The mixture was partitioned between ethyl acetate (100 mL) and water (40 mL) and the aqueous phase was extracted with ethyl acetate (2 x 50 mL). The combined organic phases were washed with brine, dried over MgS04, filtered and concentrated in vacuo. The crude residue was purified by column chromatography (light petroleum/ethyl ether 95:5), affording 12b as a yellowish solid (2.10 g, 89percent yield). Mp 70-71 °C. [CC]D +7.3 (c 1.1, CHCI3). XH-NMR (400 MHz, CDC13): delta 0.94 (3H, s, pinanyl CH»), 1.24 (1H, d, J 10.9, pinanyl Hendo), 1.36 (3H, s, pinanyl G¾), 1.53 (3H, s, pinanyl CH3), 1.64 (9H, s, f-Bu), 1.98-2.30 (5H, m, pinanyl protons), 4.51 (1H, dd, J 8.5, 2.0, CHOB), 7.46 (1Eta, t, J7.6, ¾), 8.0 (1Eta, d, J 7.6, H4), 8.12 (1H, d, J7.6, H6), 8.45 (1H, s, H2). 13C-NMR (100 MHz, CDCI3): delta 24.0, 26.5, 27.1, 28.2, 28.7, 35.5, 38.2, 39.5, 51.4, 78.4, 80.9, 86.5, 127.6, 131.5, 132.1, 135.7, 138.7, 169.5, CB not seen. EI-MS: m/z 356 (M+, 10percent), 300 (36), 283 (41), 231 (50), 204 (38), 83 (65), 67 (59), 57 (100). Anal. Calcd. for C2iH29B04: C, 70.80; H, 8.20. Found: C, 70.55; H, 8.22.
The synthetic route of 69038-74-0 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; THE REGENTS OF THE UNIVERSITY OF CALIFORNIA; UNIVERSITA’ DEGLI STUDI DI MODENA E REGGIO EMILIA; SHOICHET, Brian K.; PRATI, Fabio; CASELLI, Emilia; ROMAGNOLI, Chiara; EIDAM, Oliv; WO2013/56163; (2013); A1;,
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