5-iodo-4-Methylpyridin-2-ol synthesis

Yield:944718-23-4 21%

Reaction Conditions:

with iodine;sodium carbonate in water at 70;

Steps:

555.A

Example 555: Part A: Compound 555B was prepared according to a modification of a procedure described in WO-9846609. A mixture of 2-hydroxy-4-methylpyridine 555A (1.50 g, 13.7 mmol), iodine (3.68 g, 13.7 mmol) and sodium carbonate (3.06 g, 28.9 mmol) in water (70 mL) was heated at 70 ⁰C overnight. The mixture was acidified with concentrated HCI to pH=3, and the resulting brown solid residue was washed twice with ethyl acetate, and then taken in hot ethanol. The solid which did not dissolve (diiodo byproduct) was filtered off, and the ethanol filtrate was concentrated to give the desired product 555B as a white solid (0.67 g, 21%); HPLC-MS t_R = 1 min (UV₂₅₄ nm); mass calculated for formula C₆H₆INO 234.95, observed LCMS m/z 236.0.

References:

WO2007/84451,2007,A1 Location in patent:Page/Page column 149