反応 #92887

反応方程式

2-amino-3-chloropyrazine

dimethyl sulfoxide

trifluoromethanesulfonic anhydride

→

2

収率 79.0%

S,S-Dimethyl-N-(3-chloropyrazin-2-yl)sulfilimine

収率 79.0%

溶媒

methylene chloride

methylene chloride

反応条件

後処理

1. 1
   その他to afford a white precipitate
2. 2
   その他The reaction mixture is then quenched with 50 ml of 5% aqueous sodium bicarbonate solution
3. 3
   workup.STIRRINGstirred at -5° for 5 minutes
4. 4
   workup.ADDITIONThe reaction mixture is diluted with 200 ml methylene chloride
5. 5
   その他the phases are separated
6. 6
   抽出The aqueous phase is extracted with 250 ml methylene chloride
7. 7
   洗浄the combined organic phases are washed with 3×75 ml portions of water
8. 8
   乾燥dried over anhydrous sodium sulfate
9. 9
   その他The solvent is removed from the rotary evaporator

実験手順

To a mechanically stirred solution of 3.9 g (0.05 mol) dimethyl sulfoxide in 30 ml dry methylene chloride at -78° under nitrogen is added 13.1 g (0.046 mol) trifluoromethanesulfonic anhydride dropwise to afford a white precipitate. To this is added a solution of 5.0 g (0.039 mol) 2-amino-3-chloropyrazine (1) in 30 ml methylene chloride/15 ml dimethyl sulfoxide and the resulting solution is stirred at -78° for 2 hours and at -55° for 1 hour. The reaction mixture is then quenched with 50 ml of 5% aqueous sodium bicarbonate solution and stirred at -5° for 5 minutes. The reaction mixture is diluted with 200 ml methylene chloride and the phases are separated. The aqueous phase is extracted with 250 ml methylene chloride and the combined organic phases are washed with 3×75 ml portions of water and dried over anhydrous sodium sulfate. The solvent is removed from the rotary evaporator to give 5.8 g (79%) of 2 as yellow crystals, m.p. 106°-108°.

出典