反応 #1121793

反応方程式

bromopropionaldehyde dimethyl acetal

( 1 )

4-Bromo-pyridine-2-carboxylic acid methoxy-methyl-amide

→

1-(4-Bromo-pyridin-2-yl)-4,4-dimethoxy-butan-1-one

溶媒

THF

water

dry ice

THF

反応条件

後処理

1. 1
   乾燥dried round bottom flask at −70° C. (acetone-dry ice bath)
2. 2
   workup.ADDITIONis slowly added the Grignard reagent
3. 3
   温度maintaining internal temperature around −68° C. to −70° C
4. 4
   その他removed
5. 5
   workup.ADDITIONThe mixture is poured into a separatory funnel
6. 6
   抽出the mixture is extracted 3 times with ethyl acetate (150 mL)
7. 7
   乾燥dried over Na2SO4
8. 8
   その他the solvent evaporated
9. 9
   その他leaving a thick yellow oil (11 g, 100% crude yield, MS ES+258.02)

実験手順

To a solution of (1) (8.86 g, 36.2 mmole) in 250 mL of anhydrous THF in a 3-neck flamed dried round bottom flask at −70° C. (acetone-dry ice bath) is slowly added the Grignard reagent prepared from bromopropionaldehyde dimethyl acetal (16.5 g, 90.4 mmol) and Mg turnings (4.39 g, 181 mmol) in anhydrous THF (250 mL), maintaining internal temperature around −68° C. to −70° C. After stirring at −70° C. for 2 hours, the reaction mixture is diluted with 200 mL of water with the dry ice bath removed. The mixture is poured into a separatory funnel, and the mixture is extracted 3 times with ethyl acetate (150 mL). The organic layers are combined and dried over Na2SO4 and the solvent evaporated leaving a thick yellow oil (11 g, 100% crude yield, MS ES+258.02).

出典