Oxalyl chloride → Methyl 2-bromothiophene-3-carboxylate

HRID 2420948Notes

Reaction equation

HRID 2420948 reaction equation
[Br:1][C:2]1[S:3][CH:4]=[CH:5][C:6]=1[C:7]([OH:9])=[O:8].[C:10](Cl)(=O)C(Cl)=O>C(Cl)Cl.CN(C=O)C>[Br:1][C:2]1[S:3][CH:4]=[CH:5][C:6]=1[C:7]([O:9][CH3:10])=[O:8]

Participants

5

Reactant 2

HCID 65578Oxalyl chlorideHCID 123209712-Bromothiophene-3-carboxylic acid

Product 1

HCID 53302196Methyl 2-bromothiophene-3-carboxylateYield 98.1%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Procedure

2-bromo-3-thiophene carboxylic acid (1.0 eq, 12.56 g, 60.66 mmol) was suspended in CH2Cl2 (200 ml). Oxalyl chloride (1.1 eq, 5.9 ml, 67.16 mmol) and 5 drops of DMF were added, inducing formation of gas. The mixture was stirred overnight at room temperature and the volatiles were removed in vacuo. The resulting solid was suspended in dry methanol (150 ml) and the mixture heated to ebullition. Evaporation of the solvents afforded methyl 2-bromo-3-thiophene carboxylate (13.16 g, 98% yield) as a crude brown oil. LCMS (ES): 99% pure, m/z not detected; 1H NMR (CDCl3, 400 MHz) δ 3.88 (s, 3H), 7.23 (d, J=5.6, 1H), 7.56 (d, J=5.6, 1H) ppm.

Workup

  1. customthe volatiles were removed in vacuo
  2. temperaturethe mixture heated to ebullition
  3. customEvaporation of the solvents

Sources & evidence

ORD record
ord-6acd89cbe8544a8bbf8d2fa502478bea
Source dataset
uspto-grants-2011_06
Patent number
US07956064B2

Reaction notes

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