Trimethyl borate → [4-(Tert-butoxycarbonyl)-2,6-diethoxyphenyl]boronic acid

HRID 1097013Notes

Reaction equation

HRID 1097013 reaction equation
Br[C:2]1[C:14]([O:15][CH2:16][CH3:17])=[CH:13][C:5]([C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7])=[CH:4][C:3]=1[O:18][CH2:19][CH3:20].[Li]CCCC.[B:26](OC)([O:29]C)[O:27]C>C1COCC1>[C:9]([O:8][C:6]([C:5]1[CH:13]=[C:14]([O:15][CH2:16][CH3:17])[C:2]([B:26]([OH:29])[OH:27])=[C:3]([O:18][CH2:19][CH3:20])[CH:4]=1)=[O:7])([CH3:12])([CH3:11])[CH3:10]

Participants

5

Reactant 3

HCID 8470Trimethyl borateHCID 57930980Tert-butyl 4-bromo-3,5-diethoxybenzoateHCID 178418339Butyllithium

Product 1

HCID 57930902[4-(Tert-butoxycarbonyl)-2,6-diethoxyphenyl]boronic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of tert-butyl 4-bromo-3,5-diethoxybenzoate (1 g) in THF (20 ml) was added n-BuLi (1.6M in hexane, 3.6 ml) at −78° C. under argon atmosphere and stirred at the same temperature for 1 h. To the mixture was added B(OMe)3 (777 ul) at −78° C. and the mixture was allowed to warm up to at room temperature. After stirring for further 1 h, the mixture was poured into ice-HCl aq., extracted with EtOAc, washed with brine and dried over sodium sulphate. After filtration and concentration, the residue was purified by silicagel column chromatography (hexane/EtOAc) to give the title product as a colorless solid.

Workup

  1. stirringAfter stirring for further 1 h
  2. extractionextracted with EtOAc
  3. washwashed with brine
  4. dry with materialdried over sodium sulphate
  5. filtrationAfter filtration and concentration
  6. customthe residue was purified by silicagel column chromatography (hexane/EtOAc)

Sources & evidence

ORD record
ord-f155497fadb94735a163c0e63db5a93d
Source dataset
uspto-grants-2012_03
Patent number
US08138197B2

Reaction notes

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