Carbon tetrabromide → 2-(2,2-Dibromo-vinyl)benzo[b]thiophene

Beteiligte Stoffe

Reaktionsschritte

A solution of benzo[b]thiophene-2-carbaldehyde (1.0 g, 6.17 mmol) and carbon tetrabromide (3.1 g, 9.25 mmol) in methylene chloride (50 mL) was cooled to 0° C. A solution of triphenylphosphine (4.86 g, 18.3 mmol) in methylene chloride (20 mL) was added dropwise. After ½ hour the solution was placed on a plug of silica gel and eluted with 20% ethyl acetate:hexane. Concentration of the eluent resulted in the isolation of 1.3 g (67%) of 2-(2,2-Dibromo-vinyl)-benzo[b]thiophene as a yellow oil, which was used as such in the next step.

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