Trimethyl borate → 2-Butyloxy-3,5-di-tert-butylphenylboronic acid

HRID 1394621Notes

Reaction equation

HRID 1394621 reaction equation
[CH2:1]([O:5][C:6]1[C:11](I)=[CH:10][C:9]([C:13]([CH3:16])([CH3:15])[CH3:14])=[CH:8][C:7]=1[C:17]([CH3:20])([CH3:19])[CH3:18])[CH2:2][CH2:3][CH3:4].C([Li])(C)(C)C.[B:26](OC)([O:29]C)[O:27]C>COCCOC>[CH2:1]([O:5][C:6]1[C:7]([C:17]([CH3:20])([CH3:19])[CH3:18])=[CH:8][C:9]([C:13]([CH3:16])([CH3:15])[CH3:14])=[CH:10][C:11]=1[B:26]([OH:29])[OH:27])[CH2:2][CH2:3][CH3:4]

Participants

5

Reactant 3

HCID 8470Trimethyl borateHCID 179528162-Butoxy-1,5-di-tert-butyl-3-iodo-benzeneHCID 178418306HCID 178418306, compound

Product 1

HCID 223454122-Butyloxy-3,5-di-tert-butylphenylboronic acidYield 98%

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Conditions

Temperature
-75 °C

Procedure

2-Butoxy-1,5-di-tert-butyl-3-iodo-benzene (3.88 g, 10 mmol) was dissolved in anhydrous 1,2-dimethoxy-ethane (55 mL under a nitrogen atmosphere. The solution was cooled to −75° C. and t-butyl lithium (14.7 mL, 25 mmol, 1.7M in pentane) was added dropwise over 20-25 min at −72° C. to −69° C. The reaction was stirred at −72° C. for 45 min and then treated with trimethyl borate (5.7 mL, 50 mmol). The reaction was kept cold for 1 h and then the bath was removed and the reaction allowed to warm to room temperature over 24 h. It was treated with 1N hydrochloric acid (35 mL) and stirred for 30 min. The reaction was then diluted with water (200 mL) and extracted with ethyl acetate (150 mL, 2×100 mL). The combined organic portions were washed with bicarbonate solution (100 mL), water (150 mL), brine (150 mL), dried (Na2SO4), filtered and evaporated in vacuo to provide 3.0 g of an oil. The material was purified by flash chromotography (eluet: (9:1) hexane:ethyl acetate and (4:1) hexane:ethyl acetate) to provide 2.04 g (67%) of a white solid. Mp: 82-91° C. 1H NMR (250 MHz, CDCl3): δ 7.66 (d, 1H, J=2.6), 7.48 (d, 1H, J=2.6), 5.75 (s, 1H), 3.84 (t, 2H, J=7.1), 1.84 (m, 2H), 1.47 (m, 2H), 1.42 (s, 9H), 1.33 (s, 9H), 2.66 (t, 3H, J=7.3). MS [EI+] 307 (M+H)+[EI−] 305 (M−H)+.

Workup

  1. waitThe reaction was kept cold for 1 h
  2. customthe bath was removed
  3. temperatureto warm to room temperature over 24 h
  4. additionIt was treated with 1N hydrochloric acid (35 mL)
  5. stirringstirred for 30 min
  6. additionThe reaction was then diluted with water (200 mL)
  7. extractionextracted with ethyl acetate (150 mL, 2×100 mL)
  8. washThe combined organic portions were washed with bicarbonate solution (100 mL), water (150 mL), brine (150 mL)
  9. dry with materialdried (Na2SO4)
  10. filtrationfiltered
  11. customevaporated in vacuo

Sources & evidence

ORD record
ord-f81966e10f8742629ee9a0ddf429811f
Source dataset
uspto-grants-2008_03
Patent number
US07348359B2

Reaction notes

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