反応 #57110

反応方程式

triphenylphosphine

benzo[b]thiophene-2-carbaldehyde

carbon tetrabromide

→

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

収率 67.0%

溶媒

methylene chloride

methylene chloride

反応条件

後処理

1. 1
   洗浄eluted with 20% ethyl acetate

実験手順

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.

出典