反应详情

A solution of 3-methylpyrazine-2-carboxylic acid (10 g, 72.4 mmol) in 80 mL methanol and sulfuric acid, 95% (5 ml, 90 mmol) was heated to 60° C. for 4 h. The solution was concentrated to remove MeOH, the residue was dissolved in 50 mL of water and neutralized with 10% aq Na2CO3 solution to pH 12. The resulting solution was extracted with ethyl acetate. The combined organics were dried and concentrated to give crude methyl 3-methylpyrazine-2-carboxylate (9.1 g, 83% yield) which was used for next step without further purification.

1. concentrationThe solution was concentrated
2. customto remove MeOH
3. dissolutionthe residue was dissolved in 50 mL of water and neutralized with 10% aq Na2CO3 solution to pH 12
4. extractionThe resulting solution was extracted with ethyl acetate
5. customThe combined organics were dried
6. concentrationconcentrated