Hydrazine → 4-Bromo-2-hydrazinyl-3-iodopyridine

Temperature

20 °C

To a solution of 4-bromo-2-fluoro-3-iodopyridine (29 g, 96 mmol) in THF (300 mL) was added hydrazine (anhydrous, 30 mL, 960 mmol) at 20° C. The reaction mixture was stirred at 20° C. for 2 h. The reaction was monitored by HPLC (acetonitrile-water-TFA) and completed in 2 h. The reaction mixture was concentrated in vacuo to reduce volume by 70% and H2O (300 mL) was then added. The resulting mixture was filtered and the collected solid (1st crop) was washed with H2O. The filtrate was concentrated in vacuo to remove most of the THF. Newly formed solid was then filtered. This 2nd crop was washed with H2O. The two crops were combined and dried under high vacuum to obtain the title compound as an off-white, fluffy solid (28.6 g, 91 mmol). MS: [M+H]+=313.9. 1H NMR (400 MHz, CDCl3) δ 6.97 (d, J=5.50 Hz, 1H), 7.92 (d, J=4.95 Hz, 1H).

1. waitcompleted in 2 h
2. concentrationThe reaction mixture was concentrated in vacuo
3. additionwas then added
4. filtrationThe resulting mixture was filtered
5. washthe collected solid (1st crop) was washed with H2O
6. concentrationThe filtrate was concentrated in vacuo
7. customto remove most of the THF
8. filtrationNewly formed solid was then filtered
9. washThis 2nd crop was washed with H2O
10. customdried under high vacuum

ORD record

ord-d58f7f78acb14c3689adfdf6eb187b0f

Source dataset

uspto-grants-2009_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07572808B2