Sodium Chloride → 4,4,5,5-Tetramethyl-2-(2-methylbenzo[d][1,3]dioxol-5-yl)-1,3,2-dioxaborolane

HRID 1746050Notes

Reaction equation

Br[C:2]1[CH:11]=[CH:10][C:5]2[O:6][CH:7]([CH3:9])[O:8][C:4]=2[CH:3]=1.[Li]CCCC.C(O[B:21]1[O:25][C:24]([CH3:27])([CH3:26])[C:23]([CH3:29])([CH3:28])[O:22]1)(C)C.[NH4+].[Cl-].[Na+].[Cl-]>O1CCCC1.C(OCC)(=O)C>[CH3:28][C:23]1([CH3:29])[C:24]([CH3:27])([CH3:26])[O:25][B:21]([C:2]2[CH:11]=[CH:10][C:5]3[O:6][CH:7]([CH3:9])[O:8][C:4]=3[CH:3]=2)[O:22]1

Participants

Conditions

Temperature: -70 °C

Procedure

5-Bromo-2-methylbenzo[d][1,3]dioxole (1.0 g, 4.7 mmol, prepared as described in Matyus, Peter; Magyar, Kalman; Pihlavista, Marjo; Gyires, Klara; Haider, Norbert; Wang, Yinghua; Woda, Patrick; Dunkel, Petra; Toth-Sarudy, Eva; Turos, Gyoergy, WO2010029379) was dissolved in dry tetrahydrofuran (10 mL), cooled to −70° C. and treated with n-BuLi (2.5 M; 2.1 mL, 4.7 mmol) over 5 min. After 1 h, 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.1 g, 6.0 mmol) was added and the mixture was stirred for 90 min at −70 to −30° C. After addition of saturated NH4Cl (5 mL), the mixture was shaken with ethyl acetate (40 mL) and saturated NaCl (10 mL), dried (Na2SO4) and evaporated. The material was purified by chromatography on silica with a 0-30% ethyl acetate-hexane gradient to give the title compound (730 mg, 59%): 1H NMR (400 MHz, CDCl3) δ 7.33 (dd, J=7.7, 1.1 Hz, 1H), 7.18 (d, J=0.9 Hz, 1H), 6.77 (d, J=7.8 Hz, 1H), 6.25 (q, J=5.0 Hz, 1H), 1.66 (d, J=4.9 Hz, 3H), 1.32 (s, 12H); EIMS m/z 262.

Workup

dry with materialdried (Na2SO4)
customevaporated
customThe material was purified by chromatography on silica with a 0-30% ethyl acetate-hexane gradient

Sources & evidence

ORD record: ord-4ad6a2e5c18f464fa31f2640b42e432b
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09149038B2

Reaction notes

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