Sodium Hydroxide → 4-Iodopyridine-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-chloropicolinic acid methyl ester (2.4 g, 14.1 mmol), 57% hydriodic acid (13.3 mL) and 50% aqueous hypophosphorous acid (0.66 mL) was stirred at 85° C. for 2 h and then was stirred at 107° C. overnight. The mixture was cooled to 95° C. At this temperature were added in 30 minutes 10 M sodium hydroxide aqueous solution (4.2 mL), followed by the addition of water (15.2 mL). The mixture was cooled to rt, stirred for 1 h during which time product precipitates. The precipitate was filtered, washed with cold water and dried under high vacuum overnight to give a yellow solid 11a, 4-Iodopicolinic acid (3.5 g, 66%): 1H NMR (300 MHz, DMSO d6) δ 8.39 (d, J=5.1, 1), 8.35 (d, J=1.8, 1), 8.07 (dd, J=1.7, 5.2, 1); MS (ESPOS): 250.2 [M+H]+.

Provenance & Evidence