Reaction #657251

Reaction equation

ammonium chloride

n-butyllithium

19

5,7-Dibromo-2,3-dihydrobenzofuran

N,N-dimethylformamide

→

crystals

Yield 27.1%

5-Bromo-2,3-dihydrobenzofuran-7-carbaldehyde

Yield 27.1%

Solvents

THF

Conditions

Workup

1. 1
   Otherwas degassed at −78° C.
2. 2
   OtherThe solvent was removed
3. 3
   Washwashed with water (3×50 mL)
4. 4
   Dryingthen dried with anhydrous sodium sulfate
5. 5
   OtherSolvent removal

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.

Source