Diethyl Carbonate → Ethyl benzo[b]thiophene-7-carboxylate

HRID 1783971Notes

Reaction equation

HRID 1783971 reaction equation
Br[C:2]1[C:7]2[S:8][CH:9]=[CH:10][C:6]=2[CH:5]=[CH:4][CH:3]=1.[Mg].[C:12](=O)([O:16]CC)[O:13][CH2:14][CH3:15].[Cl-].[NH4+]>C1COCC1>[CH2:14]([O:13][C:12]([C:2]1[C:7]2[S:8][CH:9]=[CH:10][C:6]=2[CH:5]=[CH:4][CH:3]=1)=[O:16])[CH3:15]

Participants

6

Reactant 4

HCID 7766Diethyl CarbonateHCID 25517Ammonium ChlorideHCID 5462224Magnesium2×HCID 120455387-Bromobenzo[b]thiophene

Product 1

HCID 49758023Ethyl benzo[b]thiophene-7-carboxylateYield 71%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

7-bromobenzo[b]thiophene (500 mg, 2.36 mmol) is dissolved in dry THF (5.0 mL) under nitrogen. Magnesium turnings (530 mg, 2.83 mmol, 1.20 equiv.) are added and the resulting mixture is heated at reflux until dissolution of the magnesium has occurred. The resulting cloudy yellow solution is allowed to cool to rt and diethyl carbonate (2 mL, excess) is added and stirring continued for one hour, when ammonium chloride (10% aq) is added. The resulting mixture is partitioned between DCM and water and the aqueous layer is extracted with DCM. The organic fractions are combined, washed with brine, dried over Na2SO4 and adsorbed onto silica. Purification by LC using 8/2 cyclohexane/dichloromethane as the eluent afforded the title compound as a pale orange oil (346.2 mg, 71%).

Workup

  1. temperaturethe resulting mixture is heated
  2. customThe resulting mixture is partitioned between DCM and water
  3. extractionthe aqueous layer is extracted with DCM
  4. washwashed with brine
  5. dry with materialdried over Na2SO4
  6. customPurification by LC

Sources & evidence

ORD record
ord-8557a574f6614ac88eef6422d26425a2
Source dataset
uspto-grants-2009_03
Patent number
US07501411B2

Reaction notes

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