Water → 5-Bromo-3-cyanomethyl-benzo[B]thiophene

Reaction equation

[C-:1]#[N:2].[Na+].O.[Br:5][C:6]1[CH:7]=[CH:8][C:9]2[S:13][CH:12]=[C:11]([CH2:14]Br)[C:10]=2[CH:16]=1>C(O)C>[Br:5][C:6]1[CH:7]=[CH:8][C:9]2[S:13][CH:12]=[C:11]([CH2:14][C:1]#[N:2])[C:10]=2[CH:16]=1

Participants

Procedure

A mixture of 0.115 gm (2.34 mMol) sodium cyanide, 2 mL ethanol and 1 mL water was heated to reflux. To this refluxing mixture was added a solution of 0.356 gm (1.16 mMol) 5-bromo-3-(bromomethyl)benzothiophene in 4 mL ethanol. The resulting mixture was heated at reflux for 3 hours. The reaction mixture was cooled to room temperature and then partitioned between water and ethyl acetate. The phases were separated and the aqueous phase extracted with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated under reduced pressure. The residue was subjected to flash silica gel chromatography, eluting with hexane containing 10% dichloromethane and 5% ethyl acetate. Fractions containing product were combined and concentrated under reduced pressure to provide 0.214 gm (73%) of the desired nitrile as a solid.