4-Benzyloxy-3-ethyl-5-methyl-benzoic acid tert-butyl ester → 3-Ethyl-4-hydroxy-5-methyl-benzoic acid tert-butyl ester

HRID 1958793Notes

Reaction equation

HRID 1958793 reaction equation
[C:1]([O:5][C:6](=[O:24])[C:7]1[CH:12]=[C:11]([CH3:13])[C:10]([O:14]CC2C=CC=CC=2)=[C:9]([CH2:22][CH3:23])[CH:8]=1)([CH3:4])([CH3:3])[CH3:2]>C1COCC1.C(O)C.[Pd]>[C:1]([O:5][C:6](=[O:24])[C:7]1[CH:12]=[C:11]([CH3:13])[C:10]([OH:14])=[C:9]([CH2:22][CH3:23])[CH:8]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 1

HCID 669320094-Benzyloxy-3-ethyl-5-methyl-benzoic acid tert-butyl ester

Product 1

HCID 669319843-Ethyl-4-hydroxy-5-methyl-benzoic acid tert-butyl esterYield 109.3%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-benzyloxy-3-ethyl-5-methyl-benzoic acid tert-butyl ester (9.02 g, 27.6 mmol) in THF (50 mL) and ethanol (50 mL), Pd/C (400 mg, 10% Pd) is added. The slurry is stirred at rt for 24 h under 1 bar of H2. The catalyst is removed by filtration and the filtrate is concentrated, dissolved again in THF (50 mL) and ethanol (50 mL), and again treated with Pd/C (400 mg, 10% Pd). The slurry is stirred at rt for 24 h under 1 bar of H2. The catalyst is again removed by filtration and the filtrate is concentrated and dried to give 3-ethyl-4-hydroxy-5-methyl-benzoic acid tert-butyl ester as a pale yellow oil (7.13 g). LC-MS: tR=1.01 min; 1H NMR (CDCl3): δ 1.28 (t, J=7.8 Hz, 3H), 1.61 (s, 9H), 2.30 (s, 3H), 2.67 (q, J=7.5 Hz, 2H), 5.13 (br s, 1H), 7.67 (s, 1H), 7.69 (s, 1H).

Workup

  1. customThe catalyst is removed by filtration
  2. concentrationthe filtrate is concentrated
  3. dissolutiondissolved again in THF (50 mL)
  4. additionethanol (50 mL), and again treated with Pd/C (400 mg, 10% Pd)
  5. stirringThe slurry is stirred at rt for 24 h under 1 bar of H2
  6. customThe catalyst is again removed by filtration
  7. concentrationthe filtrate is concentrated
  8. customdried

Sources & evidence

ORD record
ord-475608cfa1114e5e9d8218023d99d83a
Source dataset
uspto-grants-2013_04
Patent number
US08410151B2

Reaction notes

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