Reacción #1121793

Ecuación de reacción

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

Disolventes

THF

water

dry ice

THF

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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).

Fuente