Reaction #1833213

Reaction equation

Methyl 4-amino-3,6-dichloropicolinate

periodic acid

iodine

→

title compound

Methyl 4-amino-3,6-dichloro-5-iodopicolinate

Solvents

methanol

Conditions

Workup

1. 1
   ConcentrationThe reaction mixture was concentrated
2. 2
   workup.ADDITIONdiluted with diethyl ether
3. 3
   Washwashed twice with saturated aqueous sodium bisulfate
4. 4
   ExtractionThe aqueous layers were extracted once with diethyl ether
5. 5
   Dryingthe combined organic layers were dried over anhydrous sodium sulfate
6. 6
   ConcentrationThe product was concentrated
7. 7
   Otherpurified by flash chromatography (silica gel, 0-50% ethyl acetate/hexanes)

Procedure

Methyl 4-amino-3,6-dichloropicolinate (10.0 g, 45.2 millimoles (mmol)), periodic acid (3.93 g, 17.2 mmol), and iodine (11.44 g, 45.1 mmol) were dissolved in methanol (30 mL) and stirred at reflux at 60° C. for 27 h. The reaction mixture was concentrated, diluted with diethyl ether, and washed twice with saturated aqueous sodium bisulfate. The aqueous layers were extracted once with diethyl ether, and the combined organic layers were dried over anhydrous sodium sulfate. The product was concentrated and purified by flash chromatography (silica gel, 0-50% ethyl acetate/hexanes) to provide the title compound as a pale yellow solid (12.44 g, 79%): mp 130.0-131.5° C.; 1H NMR (400 MHz, CDCl3) δ 5.56 (s, 2H), 3.97 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 163.80, 153.00, 152.75, 145.63, 112.12, 83.91, 53.21; EIMS m/z 346.

Source