Sodium Hydroxide → 4-Iodopyridine-2-carboxylic acid

Temperature

85 °C

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]+.

1. stirringwas stirred at 107° C. overnight
2. temperatureThe mixture was cooled to 95° C
3. temperatureThe mixture was cooled to rt
4. stirringstirred for 1 h during which time product
5. customprecipitates
6. filtrationThe precipitate was filtered
7. washwashed with cold water
8. customdried under high vacuum overnight

ORD record

ord-9694b9a8a24d416db59f6c7e0ab5a45e

Source dataset

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07256177B2