Acetic Acid → Ethyl 5-bromothiophene-2-carboxylate

HRID 1651312Notes

Reaction equation

HRID 1651312 reaction equation
[Br:1][C:2]1[S:6][C:5]([CH:7]=[O:8])=[CH:4][CH:3]=1.[C-]#N.[Na+].[C:12](O)(=[O:14])[CH3:13]>[O-2].[O-2].[Mn+4].C(O)C>[Br:1][C:2]1[S:6][C:5]([C:7]([O:14][CH2:12][CH3:13])=[O:8])=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 8929Sodium CyanideHCID 784285-Bromothiophene-2-carbaldehyde

Product 1

HCID 605723Ethyl 5-bromothiophene-2-carboxylate

Reagents, catalysts & solvents 2

HCID 178418406HCID 178418406, compoundCatalystHCID 702EthanolSolvent

Procedure

To 1.092 g (5.7157 mmol) of 5-bromothiophene-2-carboxaldehyde was added sequentially, 1.507 g (30.75 mmol) sodium cyanide, 60 ml ethanol, 602.5 mg (10.04 mmol) of acetic acid and 10.62 g (122.16 mmol) of manganese dioxide. This mixture was stirred at room temperature for 24 hours, then filtered through celite and the residue washed several times with ether. The combined filtrates were concentrated, then the residue taken up in water and extracted with 3×75 ml ether. Combined ether extracts were washed with saturated NaHCO3, saturated NaCl, dried (MgSO4), concentrated in vacuo and kugelrohr distilled (70° C.; 0.1 mm) to give the captioned compound as a pale yellow oil. PMR (CDCl3); δ1.3 (3H, t, J~7 Hz), 4.35 (2H, t, J~7 Hz), 7.12 (1H, d, J~4 Hz), 7.6 (1H, d, J~4 Hz).

Workup

  1. filtrationfiltered through celite
  2. washthe residue washed several times with ether
  3. concentrationThe combined filtrates were concentrated
  4. extractionextracted with 3×75 ml ether
  5. washCombined ether extracts were washed with saturated NaHCO3, saturated NaCl
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated in vacuo and kugelrohr
  8. distillationdistilled (70° C.; 0.1 mm)

Sources & evidence

ORD record
ord-ae3abb732bd94455b4d9431b1245d3f3
Source dataset
uspto-grants-1990_05
Patent number
US04927947

Reaction notes

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