反应详情

To a solution of methyl 4-amino-6-(1-ethoxyvinyl)-3-methoxypicolinate (1.68 g, 6.66 mmol) in THF (44.4 ml) was added a 2 N solution of hydrochloric acid (6.66 ml, 13.32 mmol). The milky solution was stirred at room temperature overnight. The clear yellow reaction mixture was concentrated. The residue was poured into saturated NaHCO3 and extracted with EtOAc (3×). The combined organic layers were dried over MgSO4, filtered, concentrated and dried in vacuo to afford methyl 6-acetyl-4-amino-3-methoxypicolinate (1.55 g, 6.91 mmol, 104% yield) as an orange solid which was used without further purification in the next step. ESIMS m/z 223 ([M−H]−); 1H NMR (400 MHz, CDCl3) δ 7.47 (s, 1H), 4.59 (s, 2H), 4.01 (s, 3H), 3.90 (s, 3H), 2.67 (s, 3H).

1. concentrationThe clear yellow reaction mixture was concentrated
2. additionThe residue was poured into saturated NaHCO3
3. extractionextracted with EtOAc (3×)
4. dry with materialThe combined organic layers were dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customdried in vacuo