N,N,N',N'-Tetramethylethylenediamine → tert-Butyl 5-formylthiophene-2-carboxylate

HRID 742307Notes

Reaction equation

HRID 742307 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7].CN(C)CCN(C)C.[C:21](=O)=[O:22].CC(C)=O.C([Li])(C)(C)C>CCCCC.CN(C)C=O>[CH:21]([C:5]1[S:1][C:2]([C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7])=[CH:3][CH:4]=1)=[O:22]

Participants

7

Reactant 4

HCID 8037N,N,N',N'-TetramethylethylenediamineHCID 13495746tert-Butyl thiophene-2-carboxylateHCID 18522661Acetone cardiceHCID 178418306HCID 178418306, compound

Product 1

HCID 21473735tert-Butyl 5-formylthiophene-2-carboxylate

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8003PentaneSolvent

Procedure

A solution of t-butyl 2-thiophenecarboxylate (1.84 g, 10 mmol) and N,N,N',N'-tetramethylethylenediamine (1.74 g, 15 mmol) in anhydrous tatrahydrofuran was stirred in a nitrogen stream under cooling with dry ice/acetone, followed by the dropwise addition of a 1.7M solution (8.0 ml) of t-butyllithium (13.6 mmol) in pentane. The obtained mixture was stirred as such for about 50 minutes. Anhydrous dimethylformamide (15 ml) was gradually dropped into the resulting mixture to conduct a reaction. The dry ice/acetone was removed to raise the temperature of the mixture to room one. The resulting mixture was stirred for 40 minutes and poured into 300 ml of a diethyl ether/0.3 N HCl (3:1) mixture. The obtained mixture was stirred for a while. The organic layer was recovered, washed with a phosphate buffer solution having a pH of 7 and an aqueous solution of common salt, dehydrated and distilled to remove the solvent. The residue was purified by silica gel column chromatography (developer: n-hexane/ethyl acetate=8:1) to give t-butyl 5-formyl-2-thiophenecarboxylate. yield: 1.7 g

Workup

  1. customa reaction
  2. customThe dry ice/acetone was removed
  3. temperatureto raise the temperature of the mixture to room one
  4. stirringThe resulting mixture was stirred for 40 minutes
  5. additionpoured into 300 ml of a diethyl ether/0.3 N HCl (3:1) mixture
  6. stirringThe obtained mixture was stirred for a while
  7. customThe organic layer was recovered
  8. washwashed with a phosphate buffer solution
  9. distillationdistilled
  10. customto remove the solvent
  11. customThe residue was purified by silica gel column chromatography (developer: n-hexane/ethyl acetate=8:1)

Sources & evidence

ORD record
ord-30138972fe0c4731958ad563631179bf
Source dataset
uspto-grants-1996_09
Patent number
US05554615

Reaction notes

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