Reaction #465970

Reaction equation

methyl 4,6-dibromo-3-hydroxypyridine-2-carboxylate

K2CO3

dimethyl sulfate

→

Methyl 4,6-Dibromo-3-methoxypyridine-2-carboxylate

Solvents

acetone

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was refluxed overnight
2. 2
   Concentrationconcentrated to dryness
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   OtherThe phases were separated
5. 5
   Extractionthe aqueous phase was extracted with ethyl acetate (3×100 mL)
6. 6
   DryingThe combined extracts were dried (MgSO4)
7. 7
   Concentrationconcentrated to dryness
8. 8
   OtherThe residue was purified by chromatography (silica gel)
9. 9
   WashElution with 15% ethyl acetate/hexane
10. 10
    Othergave 0.980 g

Procedure

To methyl 4,6-dibromo-3-hydroxypyridine-2-carboxylate 3.98 g (3.98 g, 12.81 mmol) in 40 mL of acetone was added K2CO3 (2.0 g, 14.47 mmol) and dimethyl sulfate (1.20 mL, 12.37 mmol). The reaction mixture was refluxed overnight and concentrated to dryness. The residue was dissolved in ethyl acetate and saturated sodium bicarbonate. The phases were separated and the aqueous phase was extracted with ethyl acetate (3×100 mL). The combined extracts were dried (MgSO4) and concentrated to dryness. The residue was purified by chromatography (silica gel). Elution with 15% ethyl acetate/hexane gave 0.980 g, of a white solid. 1H NMR(CDCl3): δ 3.95 (s, 3H); 3.90 (s, 3H); 7.80 (s, 1H).

Source