Lithium Hydroxide → 5-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid

HRID 448926Notes

Reaction equation

HRID 448926 reaction equation
C(OC(CCC[O:11][C:12](=[O:32])[C:13]1[CH:18]=[C:17]([Br:19])[C:16]([Cl:20])=[CH:15][C:14]=1[O:21][CH2:22][CH2:23][CH2:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])=O)(C)(C)C.[Li+].[OH-].OS([O-])(=O)=O.[Na+]>C1COCC1>[Br:19][C:17]1[C:16]([Cl:20])=[CH:15][C:14]([O:21][CH2:22][CH2:23][CH2:24][C:25]([O:27][C:28]([CH3:30])([CH3:29])[CH3:31])=[O:26])=[C:13]([CH:18]=1)[C:12]([OH:32])=[O:11]

Participants

5

Reactant 3

HCID 3939Lithium HydroxideHCID 516919Sodium BisulfateHCID 686035915-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid 3-tert-butoxycarbonyl-propyl ester

Product 1

HCID 686032665-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acidYield 41.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A mixture of 5-bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid 3-tert-butoxycarbonyl-propyl ester (8.2 g, 15.3 mmol) and LiOH (19.1 mL, 4 N, 76.6 mmol) in THF (150 mL) was stirred at rt for 16 hrs. The mixture was acidified by saturated NaHSO4 (50 mL) and extracted with ethyl acetate. The ethyl acetate layer was dried over Na2SO4, filtered and concentrated. The residue was purified via silica gel flash chromatography (eluting with 50% ethyl acetate in hexane), followed by crystallization in hexane/ethyl acetate (10/1) to afford 5-bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid as white crystals (2.5 g). MS [M-(iso-butene+OH)]+: 320.8; tR=2.38 min. (method 1)

Workup

  1. extractionextracted with ethyl acetate
  2. dry with materialThe ethyl acetate layer was dried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe residue was purified via silica gel flash chromatography (eluting with 50% ethyl acetate in hexane)
  6. customfollowed by crystallization in hexane/ethyl acetate (10/1)

Sources & evidence

ORD record
ord-a81ec6164d6c49c99c01e762ea4fc8ff
Source dataset
uspto-grants-2013_07
Patent number
US08481738B2

Reaction notes

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