2-Pyridinecarboxylic acid, 4,5,6-trichloro-, phenylmethyl ester synthesis

Yield:1390662-56-2 94%

Reaction Conditions:

at 100; for 4 h;Inert atmosphere;

Steps:

11.A

Example 11; Preparation of benzyl 4-amino-3-bromo-6-(4-chloro-2-fluoro-3-methoxy-phenyl)-5-fluoropicolinate (Compound 43); Step A. A mixture of methyl 4,5,6-trichloropicolinate (prepared by the methods described in U.S. Pat. No. 6,784,137 B2; 25 g, 0.10 moles (mol)) and benzyl alcohol (100 g, 0.2 mol) in a 250 mL three-neck round bottom flask was heated under nitrogen at 100° C., Titanium isopropoxide (0.6 g, 0.02 mol) was added. After 4 h at 100° C., the nearly colorless solution was cooled and transferred to a 250 mL round bottom single neck flask. Excess benzyl alcohol was removed under vacuum to give a nearly white solid (31 g, 94%): mp 125-126.5° C.; ¹H NMR (400 MHz, CDCl₃) δ 8.08 (s, 1H, pyridine H), 7.42 (m, 2H, phenyl), 7.31 (m, 3H, phenyl), 5.40 (s, 2H, CH₂Ph); ¹³C{¹H} NMR (101 MHz, CDCl₃) δ 162.0 (CO₂R), 150.4, 145.0, 144.9, 134.7, 133.1, 128.3 (phenyl CH), 125.4 (pyridine CH), 67.88 (CH₂Ph).

References:

US2012/190551,2012,A1 Location in patent:Page/Page column 8-9