Реакция #162279

Уравнение реакции

Methyl 4-amino-6-chloro-5-fluoropicolinate

periodic acid

iodine

→

title compound

Выход 194.0%

methyl 4-amino-6-chloro-5-fluoro-3-iodopicolinate

Выход 194.0%

Растворители

methyl alcohol

Условия реакции

Обработка

1. 1
   Температураheated
2. 2
   Температураat reflux for 20 h
3. 3
   ТемператураThe mixture was cooled
4. 4
   Другоеthe volatiles were removed under vacuum
5. 5
   workup.DISSOLUTIONThe residue was dissolved in EtOAc (50 mL)
6. 6
   ДругоеThe organic phase was separated
7. 7
   Промывкаwashed with satd aq NaCl (10 mL)
8. 8
   Сушкаdried (Na2SO4)
9. 9
   Другоеevaporated
10. 10
    ДругоеThe residue was purified by silica gel chromatography (5-50% EtOAc-hexane gradient)

Методика

Methyl 4-amino-6-chloro-5-fluoropicolinate (2.2 g, 10.8 mmol) was dissolved in methyl alcohol (20 mL). The solution was treated with periodic acid (880 mg, 3.9 mmol) and iodine (2.2 g, 8.6 mmol) and then heated at reflux for 20 h. The mixture was cooled, and the volatiles were removed under vacuum. The residue was dissolved in EtOAc (50 mL) and then stirred with 10% NaHSO3 solution (20 mL) for 10 min. The organic phase was separated and washed with satd aq NaCl (10 mL), dried (Na2SO4) and evaporated. The residue was purified by silica gel chromatography (5-50% EtOAc-hexane gradient) to give the title compound as a light orange solid (2.5 g, 70%): mp 149-151° C.; ESIMS m/z 330 ([M]+); 1H NMR (400 MHz, CDCl3) δ 5.17 (s, 2H, NH2), 3.97 (s, 3H, OMe); 19F NMR (376 MHz, CDCl3) δ −135.79 (s).

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