反応 #444980

反応方程式

hydrochloric acid

N-Butyllithium

5-Bromo-2-chloro-3-thiophenecarboxylic acid

iodomethane

→

2-chloro-5-methyl-3-thiophenecarboxylic acid

溶媒

water

tetrahydrofuran

反応条件

後処理

1. 1
   温度The reaction mixture was warmed to room temperature
2. 2
   workup.STIRRINGstirred at room temperature for 15 hours
3. 3
   抽出extracted with ethyl acetate
4. 4
   乾燥The extract was dried over anhydrous magnesium sulfate
5. 5
   濃縮concentrated under reduced pressure

実験手順

5-Bromo-2-chloro-3-thiophenecarboxylic acid (2.41 g) was dissolved in tetrahydrofuran (50 ml), and the mixture was cooled to -78° C. N-Butyllithium (1.6M in hexane, 14 ml) was slowly added dropwise. The mixture was stirred at -78° C. for 1 hour, and iodomethane (1.4 ml) was added dropwise. The reaction mixture was warmed to room temperature, stirred at room temperature for 15 hours, poured into water, acidified with 1N hydrochloric acid and extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give 2-chloro-5-methyl-3-thiophenecarboxylic acid (1.7 g) as crystals.

出典