Hydrochloric Acid → 3,4-Dimethylthiophene-2-carbaldehyde

HRID 1444991Notes

Reaction equation

HRID 1444991 reaction equation
C([Li])CCC.[CH3:6][C:7]1[C:11]([CH3:12])=[CH:10][S:9][CH:8]=1.CN([CH:16]=[O:17])C.Cl>CCOCC.C1COCC1>[CH:16]([C:8]1[S:9][CH:10]=[C:11]([CH3:12])[C:7]=1[CH3:6])=[O:17]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6228DimethylformamideHCID 790893,4-DimethylthiopheneHCID 178418339Butyllithium

Product 1

HCID 125183953,4-Dimethylthiophene-2-carbaldehydeYield 56%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 1.5 M n-butyllithium (3.4 mL, 5.1 mmol) in ether was added dropwise under argon to a solution of 3,4-dimethylthiophene trimer (1.62 g, 4.8 mmol, See Example 16) in dry THF (10 mL) at −70° C. and the resultant solution was warmed to −50° C. Next, 0.4 mL (5.4 mmol) of DMF was added dropwise and the mixture allowed to warm to room temperature overnight. The mixture was poured into a mixture of 1 liter of 12 M HCl and crushed in certain embodiments and thereafter extracted with ether. The organic layers were combined, washed with water, and dried over MgSO4. After evaporation of the solvent, the residue was purified by column chromatography (silica gel, hexane/CH2Cl2 (v:v) 3:1) to give the product 2-formyl-3,4-dimethylthiophene as a yellow solid (0.98 g, 56%) and recovered unreacted trimer (0.55 g). 1H NMR (CDCl3) δ 10.08 (1H, s, CHO), 6.99 (1H, s, aromatic H), 2.53 (3H, s, CH3), 2.22 (3H, s, CH3), 2.16 (3H, s, CH3), 2.13 (3H, s, CH3), 2.10 (6H, s CH3).

Workup

  1. customcrushed in certain embodiments
  2. extractionextracted with ether
  3. washwashed with water
  4. dry with materialdried over MgSO4
  5. customAfter evaporation of the solvent
  6. customthe residue was purified by column chromatography (silica gel, hexane/CH2Cl2 (v:v) 3:1)

Sources & evidence

ORD record
ord-4f66002c3b0f433285ac6bee7fd3fa34
Source dataset
uspto-grants-2010_02
Patent number
US07663301B2

Reaction notes

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