Reacción #328609

Ecuación de reacción

ethyl 5-bromo-2-methylpyridine-3-carboxylate

selenium dioxide

→

title compound

Ethyl 5-bromo-2-formylpyridine-3-carboxylate

Disolventes

1,4-dioxane

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroTo each of 106 separate 20-mL microwave vials
2. 2
   workup.ADDITIONadd
3. 3
   Otrowith microwave irradiation
4. 4
   Otrothe contents of the reaction vessels
5. 5
   Filtraciónfilter through a pad of silica gel (2 kg)
6. 6
   Lavadoand rinse the pad with DCM (3 L)
7. 7
   ConcentraciónConcentrate the combined filtrates under reduced pressure
8. 8
   OtroSplit the material into two equally-sized batches
9. 9
   Lavadoeluting with DCM
10. 10
    ConcentraciónConcentrate the filtrate under reduced pressure

Procedimiento

To each of 106 separate 20-mL microwave vials, add: ethyl 5-bromo-2-methylpyridine-3-carboxylate (5 g, 20.48 mmol, 1.0 equiv), selenium dioxide (2.98 g, 26.63 mmol, 1.3 equiv), and 1,4-dioxane (13 mL). Heat the vessels to 180° C. for 20 min with microwave irradiation. Combine the contents of the reaction vessels; filter through a pad of silica gel (2 kg); and rinse the pad with DCM (3 L). Concentrate the combined filtrates under reduced pressure. Split the material into two equally-sized batches, and pass each through a pad of silica gel (2 kg) eluting with DCM. Concentrate the filtrate under reduced pressure to furnish the title compound as a yellow or pale orange solid (473 g, 93.2% yield). MS (m/z) (79Br/81Br) 258/260 (M+1).

Fuente