Reaction #1693

Reaction equation

2-cyano-5-(hydroxymethyl)thiophene

triphenylphosphine

carbon tetrabromide

→

2-cyano-5-(bromomethyl)thiophene

Yield 75.0%

Solvents

THF

Conditions

Workup

1. 1
   Otherthe solvent was removed in vacuo
2. 2
   workup.DISSOLUTIONthe residue was dissolved in chloroform
3. 3
   WashThe product was eluted
4. 4
   workup.ADDITIONFractions containing pure product (as judged by TLC)
5. 5
   Concentrationconcentrated in vacuo

Procedure

To a solution of 2-cyano-5-(hydroxymethyl)thiophene (6.0 g, 43 mmol) in THF (50 mL) was added triphenylphosphine (15.7 g, 47 mmol) and carbon tetrabromide (12.3 g, 47 mmol). After stirring overnight under nitrogen atmosphere at room temperature, the solvent was removed in vacuo and the residue was dissolved in chloroform, then adsorbed onto silica gel and loaded onto a silica gel column. The product was eluted using an ethyl acetate/hexanes gradient. Fractions containing pure product (as judged by TLC) were pooled and concentrated in vacuo to give 6.5 g (75%) of 2-cyano-5-(bromomethyl)thiophene.

Source