反応 #7053

反応方程式

methyl alcohol

dimethylformamide

water

ethyl acetate

5-bromothiophene-2-sulfonamide

dimethylformamide

→

title compound

5-(Cyano)thiophene-2-sulfonamide

溶媒

methylene chloride

反応条件

後処理

1. 1
   workup.WAITplaced under microwave radiation (under nitrogen atmosphere at 160° C.) for 37 min
2. 2
   その他The organic phase is separated
3. 3
   抽出the aqueous layer is extracted with 20 mL ethyl acetate
4. 4
   乾燥The combined organic layers are dried over sodium sulfate
5. 5
   濃縮concentrated in vacuo
6. 6
   その他chromatographed on silica (0–5% methyl alcohol in methylene chloride)

実験手順

A mixture of 5-bromothiophene-2-sulfonamide (0.50 g, 2.1 mmol), zinc cyanide (0.25 g, 2.1 mmol), tetrakis(triphenylphosphine)palladium(0) (0.072 g, 0.06 mmol) in dimethylformamide (5 mL, anhydrous) is placed under microwave radiation (under nitrogen atmosphere, 160° C.) for 15 min. Thin layer chromatography (5% methyl alcohol in methylene chloride) demonstrates the reaction is incomplete. Additional tetrakis-(triphenylphosphine)palladium(0) (0.24 g, 0.2 mmol) and dimethylformamide (10 mL) are added to the reaction mixture and placed under microwave radiation (under nitrogen atmosphere at 160° C.) for 37 min. 10 mL of water and 20 mL of ethyl acetate are added to the reaction mixture. The organic phase is separated and the aqueous layer is extracted with 20 mL ethyl acetate. The combined organic layers are dried over sodium sulfate, concentrated in vacuo, and then chromatographed on silica (0–5% methyl alcohol in methylene chloride) to give the title compound, as a white solid (0.22 g, 57% yield).

出典