Electric Literature of 33070-32-5, A common heterocyclic compound, 33070-32-5, name is 5-Bromo-2,2-difluorobenzodioxole, molecular formula is C7H3BrF2O2, 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.
EXAMPLE 79A 2,2-difluoro-1,3-benzodioxol-5-ylboronic acid A solution of 1.5M tert-butyllithium in pentane (130 mL, 195 mmol) in diethyl ether (500 mL) at -78 C. was treated with 5-bromo-2,2-difluoro-1,3-benzodioxole (18 g, 76 mmol) in diethyl ether (80 mL), stirred for 1 hour, treated with triisopropylborate (37 mL, 160 mmol), warmed to room temperature over 1 hour, poured into 4M NaOH (700 mL), stirred for 15 minutes, cooled, adjusted to pH 1 with concentrated HCl, and extracted with ethyl acetate. The extract was washed with brine, dried (Na2SO4), filtered, and concentrated to provide 14.7 g (95%) of the desired product. 1H NMR (DMSO-d6) delta7.75 (m, 1H), 7.66 (m, 1H), 7.51 (m, 1H), 7.39 (m, 1H), 7.30 (m, 1H).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; Claiborne, Akiyo K.; Gwaltney II, Stephen L.; Hasvold, Lisa A.; Li, Qun; Li, Tongmei; Lin, Nan-Horng; Mantei, Robert A.; Rockway, Todd W.; Sham, Hing L.; Sullivan, Gerard M.; Tong, Yunsong; Wang, Gary; Wang, Le; Wang, Xilu; Wang, Wei-Bo; US2003/87940; (2003); A1;,
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