Carbon tetrabromide → N-benzyloxy-3-(phenylthio)acrylimidoyl bromide

Participants

Reaction Steps

Pyridine (2.7 ml) was added to THF (80 ml) solution of 3-(phenylthio)acryloyl chloride (3.0 g) and hydrochloric acid salt of O-benzylhydroxylamine (2.6 g) under ice-cooling and stirred at the same temperature for one hour and at room temperature for three hours. The reaction mixture was concentrated under reduced pressure. Chloroform (150 ml) was added to the residue, washed successively with 1N hydrochloric acid, pure water and aqueous saturated sodium chloride solution, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography (hexane:ethyl acetate 2:1) to obtain N-benzyloxy-3-(phenylthio)acrylamide (3.5 g) as colorless oil. N-benzyloxy-3-(phenylthio)acrylamide (1.0 g) was dissolved to acetonitrile (70 ml), carbon tetrabromide (2.3 g) and triphenylphosphine (1.8 g) were added thereto under ice-cooling, then heat refluxing for four hours. The reaction mixture was concentrated under reduced pressure. The residue was subjected to silica gel column chromatography (hexane:ethyl acetate 20:1) to obtain N-benzyloxy-3-(phenylthio)acrylimidoyl bromide (1.1 g) as light yellow oil.

Provenance & Evidence