Bromine → 5-Bromo-3-methylthiophene-2-carbaldehyde

HRID 2368706Notes

Reaction equation

HRID 2368706 reaction equation
[Br:1]Br.[CH3:3][C:4]1[CH:8]=[CH:7][S:6][C:5]=1[CH:9]=[O:10]>C(Cl)(Cl)Cl.C(Cl)Cl>[Br:1][C:7]1[S:6][C:5]([CH:9]=[O:10])=[C:4]([CH3:3])[CH:8]=1

Participants

5

Reactant 2

HCID 24408BromineHCID 799113-Methyl-2-thiophenecarboxaldehyde

Product 1

HCID 151154075-Bromo-3-methylthiophene-2-carbaldehydeYield 72.7%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolventHCID 6344DichloromethaneSolvent

Procedure

Bromine (104 mL, 2.02 mol) was added dropwise to a 0° C. solution of 255 g of 3-methylthiophene-2-carboxaldehyde (2.02 mol) in 1.7 L of chloroform cooled with an external ice bath. After the addition was complete, the mixture was allowed to slowly warm to room temperature, and then heated at reflux temperature for 2 hours. The red mixture was diluted with 1 L methylene chloride and successively washed with water, saturated bicarbonate solution, and brine. The organic fraction was dried over anhydrous sodium sulfate and concentrated to a red oil. The crude oil was then vacuum distilled to isolate fractions which eluted at 101-106° C. at ca. 2 torr, which produced 301 g of a pale yellow-green solid. 1H NMR (CDCl3, 200 MHz): δ=9.87 (s, 1H), 6.94 (s, 1H) 2.53 (s, 3H).

Workup

  1. temperaturecooled with an external ice bath
  2. additionAfter the addition
  3. temperatureheated
  4. temperatureat reflux temperature for 2 hours
  5. washsuccessively washed with water, saturated bicarbonate solution, and brine
  6. dry with materialThe organic fraction was dried over anhydrous sodium sulfate
  7. concentrationconcentrated to a red oil
  8. distillationvacuum distilled
  9. customto isolate fractions which
  10. washeluted at 101-106° C. at ca. 2 torr, which

Sources & evidence

ORD record
ord-5914d13cef26457889d70be8be838179
Source dataset
uspto-grants-2014_04
Patent number
US08703795B2

Reaction notes

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