Iodine → 2-Amino-5-bromo-3-iodopyridine

Temperature

100 °C

I2 (8.81 g, 34.7 mmol, 1.2 equiv.) was added to a solution of 5-bromopyridin-2-amine (5.00 g, 28.9 mmol) in DMSO (30 mL), and the resulting mixture was stirred at 100° C. for 4 h. After standing at 25° C. for 12 h, the reaction mixture was poured onto a saturated Na2S2O5 aqueous solution (20 mL), and extracted with EtOAc (3×50 mL). The combined organic layers were washed with brine, dried over anhydrous MgSO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel (hexane/EtOAc, EtOAc 15 to 25%) providing 5-bromo-3-iodopyridin-2-amine (4.00 g, 46%) as a pale yellow solid. H1 NMR (300 MHz, CDCl3): δ 8.07 (s, 1H), 7.98 (s, 1H) and 5.05 (bs, 2H). K2CO3 aqueous solution (1 M, 6.8 mL) was added to a suspension of 5-bromo-3-iodopyridin-2-amine (2.00 g, 6.69 mmol), 6-methoxypyridin-3-ylboronic acid (1.12 g, 7.32 s mmol, 1.1 equiv.), and Pd(PPh)3 (380 mg, 5 mol %) in dioxane (20 mL) under N2. The reaction mixture was stirred at 120° C. for 14 h, poured onto H2O (65 mL) and extracted with EtOAc (3×80 mL). The combined organic layers were washed with brine, dried over anhydrous MgSO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel (hexane/EtOAc, EtOAc 30 to 40%) providing intermediate 5-bromo-3-(6-methoxypyridin-3-yl)pyridin-2-amine (1′) (Formula iv) (993 mg, 53%) as a pale yellow solid.

1. waitAfter standing at 25° C. for 12 h
2. extractionextracted with EtOAc (3×50 mL)
3. washThe combined organic layers were washed with brine
4. dry with materialdried over anhydrous MgSO4
5. concentrationconcentrated in vacuo
6. customThe residue was purified by column chromatography on silica gel (hexane/EtOAc, EtOAc 15 to 25%)

ORD record

ord-5586e43442ae4b448575194ca0b9baa0

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09024033B2