Iodine → 4-Allyl-3,5-bis-benzyloxy-benzoic acid tert-butyl ester

HRID 1177193Notes

Reaction equation

HRID 1177193 reaction equation
II.[CH:3]([Mg]Br)([CH3:5])[CH3:4].[Li]CCCC.[C:13]([O:17][C:18](=[O:42])[C:19]1[CH:24]=[C:23]([O:25][CH2:26][C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[C:22](Br)=[C:21]([O:34][CH2:35][C:36]2[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=2)[CH:20]=1)([CH3:16])([CH3:15])[CH3:14].C([Cu])#N.[Li+].[Cl-].C(Br)C=C>CCOCC.C1COCC1>[C:13]([O:17][C:18](=[O:42])[C:19]1[CH:24]=[C:23]([O:25][CH2:26][C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[C:22]([CH2:5][CH:3]=[CH2:4])=[C:21]([O:34][CH2:35][C:36]2[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=2)[CH:20]=1)([CH3:16])([CH3:15])[CH3:14]

Participants

10

Reactant 7

HCID 807IodineHCID 7841Allyl bromideHCID 433294Lithium ChlorideHCID 10389923tert-Butyl 3,5-bis(benzyloxy)-4-bromobenzoateHCID 178418339ButyllithiumHCID 178418365HCID 178418365, compoundHCID 178418546HCID 178418546, compound

Product 1

HCID 595602714-Allyl-3,5-bis-benzyloxy-benzoic acid tert-butyl esterYield 76.4%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

To a suspension of Mg pieces (5.76 g, 0.24 mol) in Et2O (250 mL) was added catalytic I2, followed by i-PrMgBr (19.7 g, 0.16 mol) in one portion. The mixture was irradiated with heating. After stirring for 2 hr, the resulting solution was added to THF (200 mL). n-BuLi (128 mL, 2.5 M in hexane, 0.32 mol) was added drop wise to the mixture at 0° C. The mixture was cooled to −78° C. and 3,5-bis-benzyloxy-4-bromo-benzoic acid tert-butyl ester (200c) (50 g, 0.107 mol) was added drop wise. After the mixture was stirred for 1 hr, CuCN (2.9 g, 0.032 mol), LiCl (2.7 g, 0.064 mol) and allyl bromide (51.5 g, 0.43 mol) were added sequentially. After stirring for another 30 min at −78° C., TLC (EtOAc/petroleum oil=1/10) showed the reaction was complete. The mixture was quenched with saturated aqueous NH4Cl (150 mL). The aqueous layer was extracted with EtOAc (2×100 mL). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated to give the title compound (35 g, 76.4% yield) as a yellow oil. 1H NMR (400 MHz, CDCl3): δ 7.57-7.25 (m, 12H), 5.98 (m, 1H), 5.13 (s, 4H), 5.04-4.88 (m, 2H), 3.57 (m, 2H), 1.59 (s, 9H).

Workup

  1. customThe mixture was irradiated
  2. temperaturewith heating
  3. stirringAfter the mixture was stirred for 1 hr
  4. stirringAfter stirring for another 30 min at −78° C.
  5. customThe mixture was quenched with saturated aqueous NH4Cl (150 mL)
  6. extractionThe aqueous layer was extracted with EtOAc (2×100 mL)
  7. washThe combined organic layers were washed with brine
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-cc7cdfadd9124350b41515ad50876b0f
Source dataset
uspto-grants-2010_11
Patent number
US07842713B2

Reaction notes

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