Reaktion #162272

Reaktionsgleichung

sodium bisulfite

sodium iodide

sodium nitrite

Methyl 3-amino-4,5,6-trichloropicolinate

→

title compound

methyl 4,5,6-trichloro-3-iodopicolinate

Lösungsmittel

water

dichloromethane

Ethyl acetate

HCl

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITAfter 20 minutes
2. 2
   Sonstigethe phases were separated
3. 3
   WaschenThe organic phase was washed with saturated sodium chloride
4. 4
   Trocknendried over sodium sulfate
5. 5
   Einengenconcentrated under vacuum
6. 6
   Sonstigethe combined crude products were purified by flash chromatography (SiO2, hexane/ethyl acetate)

Vorschrift

Methyl 3-amino-4,5,6-trichloropicolinate (0.5 g, 2.0 mmol) was dissolved in concentrated HCl (20 mL), cooled to 5° C., and treated with a solution of sodium nitrite (0.2 g, 3.0 mmol dissolved in 1 mL of water) over 15 minutes. The reaction mixture was stirred for 20 minutes at 5° C. and poured carefully into a rapidly stirred mixture of sodium iodide (1.8 g; 12 mmol) in water (100 mL) and dichloromethane (30 mL). After 20 minutes, solid sodium bisulfite was added. Ethyl acetate (100 mL) was added and the phases were separated. The organic phase was washed with saturated sodium chloride, dried over sodium sulfate, and concentrated under vacuum. The above procedure was performed again on 1.5 g of the amine and the combined crude products were purified by flash chromatography (SiO2, hexane/ethyl acetate) to afford the title compound as a white solid (1.8 g 61%): mp 61-62° C.; 1H NMR (400 MHz, CDCl3) δ 4.00 (s, 3H); EIMS m/z 365.

Quelle