Bromine → Ethyl 5-bromothiophene-3-carboxylate

HRID 910280Notes

Reaction equation

HRID 910280 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[S:5]1[CH:9]=[CH:8][C:7]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[CH:6]1.[Br:15]Br>ClCCl>[Br:15][C:9]1[S:5][CH:6]=[C:7]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:8]=1

Participants

5

Reactant 3

HCID 24408BromineHCID 798243-Thiophenecarboxylic acid, ethyl esterHCID 6451240Aluminum(III) Chloride

Product 1

HCID 15293216Ethyl 5-bromothiophene-3-carboxylateYield 57.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

20 g (147 mmol) of aluminum chloride are added portionwise to a solution of 10 g (67 mmol) of ethyl thiophene-3-carboxylate in 160 ml of dichloromethane, cooled beforehand to 0° C. The reaction medium is warmed to room temperature and a solution of 4 ml (73 mmol) of bromine in 10 ml of dichloromethane is then added. After reaction for 50 minutes at room temperature, the reaction medium is poured into a water+ice mixture and extracted with dichloromethane. The organic phase is dried over magnesium sulfate, filtered and evaporated under vacuum. The residue obtained is purified by chromatography on a column of silica eluted with a 9/1 heptane/ethyl acetate mixture. 9 g (57%) of ethyl 5-bromothiophene-3-carboxylate are obtained.

Workup

  1. customThe reaction
  2. temperaturemedium is warmed to room temperature
  3. customAfter reaction for 50 minutes at room temperature
  4. extractionextracted with dichloromethane
  5. dry with materialThe organic phase is dried over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated under vacuum
  8. customThe residue obtained
  9. customis purified by chromatography on a column of silica
  10. washeluted with a 9/1 heptane/ethyl acetate mixture

Sources & evidence

ORD record
ord-2e28ad7ba0ff4be389da89efed115e15
Source dataset
uspto-grants-2011_09
Patent number
US08022079B2

Reaction notes

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