Dimethylformamide → 5-Chloro-3-methylbenzo[b]thiophene-2-carbaldehyde

HRID 1362039Notes

Reaction equation

HRID 1362039 reaction equation
[Cl:1][C:2]1[CH:11]=[CH:10][C:5]2[S:6][CH:7]=[C:8]([CH3:9])[C:4]=2[CH:3]=1.C([Li])CCC.CN([CH:20]=[O:21])C.[NH4+].[Cl-]>C1COCC1>[Cl:1][C:2]1[CH:11]=[CH:10][C:5]2[S:6][C:7]([CH:20]=[O:21])=[C:8]([CH3:9])[C:4]=2[CH:3]=1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 25517Ammonium ChlorideHCID 31731719404-18-3HCID 178418339Butyllithium

Product 1

HCID 36596315-Chloro-3-methylbenzo[b]thiophene-2-carbaldehydeYield 115.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5-chloro-3-methyl-benzo[b]thiophene (4.98 g, 27.3 mmol) in THF (50 mL) at −40° C. was added n-butyllithium (18.7 mL of a 1.6 M solution in hexanes, 30.0 mmol) dropwise. The resulting yellow solution was stirred for 1 h and then DMF (6.3 mL, 81.9 mmol) was added in one portion. The solution was warmed slowly to room temperature and stirred overnight. Saturated aqueous NH4Cl was added and the mixture was extracted with ethyl acetate (3×200 mL). The combined organics were washed with water (100 mL) and brine (100 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to give the title compound (6.62 g, 89%) as a yellow solid: 1H NMR (300 MHz, CDCl3) δ 10.32 (s, 1H), 7.85 (s, 1H), 7.79 (d, J=8.7 Hz, 1H), 7.46 (dd, J=8.7, 2.0 Hz, 1H), 2.74 (s, 3H).

Workup

  1. stirringstirred overnight
  2. extractionthe mixture was extracted with ethyl acetate (3×200 mL)
  3. washThe combined organics were washed with water (100 mL) and brine (100 mL)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-bb3e57a6886a4c7389f43a911981f967
Source dataset
uspto-grants-2011_02
Patent number
US07879872B2

Reaction notes

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