Dimethylformamide → 5-Bromo-2,3-dihydrobenzo[b]furan-7-carbaldehyde

HRID 389790Notes

Reaction equation

HRID 389790 reaction equation
[Br:1][C:2]1[CH:3]=[C:4](Br)[C:5]2[O:9][CH2:8][CH2:7][C:6]=2[CH:10]=1.C([Li])CCC.CN(C)[CH:19]=[O:20].[Cl-].[NH4+]>C1COCC1>[Br:1][C:2]1[CH:3]=[C:4]([CH:19]=[O:20])[C:5]2[O:9][CH2:8][CH2:7][C:6]=2[CH:10]=1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 25517Ammonium ChlorideHCID 27791355,7-Dibromo-2,3-dihydrobenzofuranHCID 178418339Butyllithium

Product 1

HCID 27948045-Bromo-2,3-dihydrobenzo[b]furan-7-carbaldehydeYield 27.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A sample of 19 (6.0 g, 26.5 mmol) in freshly distilled dry THF was degassed at −78° C. and n-butyllithium (25 mL of 1.05 M, 26 mmol) was added dropwise by syringe. Then N,N-dimethylformamide (2.9 mL, 26 mmol) was added dropwise via syringe. The reaction mixture was allowed to come to room temperature overnight. Saturated ammonium chloride (10 mL) was added to and the mixture was stirred for 30 minutes. The solvent was removed and the residue was taken up in dichloromethane (50 mL), and washed with water (3×50 mL) then dried with anhydrous sodium sulfate. Solvent removal yielded yellow crystals (1.6 g) which were washed with ether and recrystallized from a minimum of hot methanol to give white crystals of 20 (1.32 g, 22%) mp=99-100° C.

Workup

  1. customwas degassed at −78° C.
  2. customThe solvent was removed
  3. washwashed with water (3×50 mL)
  4. dry with materialthen dried with anhydrous sodium sulfate
  5. customSolvent removal

Sources & evidence

ORD record
ord-90909aae445a4e27ab446ade58d3ac23
Source dataset
uspto-grants-2013_02
Patent number
US08383083B2

Reaction notes

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