Lithium hydroxide, monohydrate → 5-bromo-3,4-dihydro-1H-isochromene-1-carboxylic acid

HRID 1187019Notes

Reaction equation

HRID 1187019 reaction equation
[Br:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH2:4][CH2:5][O:6][CH:7]2[C:12]([O:14]C)=[O:13].O[Li].O>CO.C1COCC1.O>[Br:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH2:4][CH2:5][O:6][CH:7]2[C:12]([OH:14])=[O:13]

Participants

4

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 66646338methyl 5-bromo-3,4-dihydro-1H-isochromene-1-carboxylate

Product 1

HCID 666464675-bromo-3,4-dihydro-1H-isochromene-1-carboxylic acid

Reagents, catalysts & solvents 1

HCID 21892291Methanol tetrahydrofuran waterSolvent

Procedure

To a solution of methyl 5-bromo-3,4-dihydro-1H-isochromene-1-carboxylate (12.1 g, 42.4 mmol) in 200 mL of MeOH/THF/H2O (2/2/1) was added LiOH.H2O (5.34 g, 0.127 mol), and the mixture was stirred at ambient temperature for 30 min. The solvents were removed under vacuum, and the residue was added 100 mL of water and extracted with ether. The aqueous layer was then acidified with 4 N HCl to pH=4˜5 in ice bath, and extracted with EtOAc. The combined organic phase was washed with brine, dried over anhydrous sodium sulfate and concentrated to afford 5-bromo-3,4-dihydro-1H-isochromene-1-carboxylic acid.

Workup

  1. customThe solvents were removed under vacuum
  2. additionthe residue was added 100 mL of water
  3. extractionextracted with ether
  4. extractionextracted with EtOAc
  5. washThe combined organic phase was washed with brine
  6. dry with materialdried over anhydrous sodium sulfate
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-a294a857008548c39ffb10e97dbb2d6b
Source dataset
uspto-grants-2014_03
Patent number
US08673920B2

Reaction notes

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