Hydrazine hydrate (1:1) → 3-Bromo-4-hydrazinylpyridine

Temperature

100 °C

A mixture of 3-bromo-4-chloropyridine (5 g, 0.026 mol) and hydrazine hydrate (80% in water, 80 mL) in dioxane (100 mL) was stirred at 100° C. overnight. After cooling down to RT, the mixture was concentrated. The residue was partitioned between 300 mL of EA and 300 mL of aq. sat. NH4Cl. The organic layer was washed with brine, dried over Na2SO4, filtered and concentrated to get crude product which was suspended in 30 mL of cold isopropyl alcohol and filtered. The collected solid was dried in air to get 4.2 g (87%) of 3-bromo-4-hydrazinylpyridine as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 8.18 (s, 1H), 8.07 (d, J=5.6 Hz, 1H), 7.37 (s, 1H), 7.01 (d, J=5.6 Hz, 1H), 4.36 (s, 2H).

1. temperatureAfter cooling down to RT
2. concentrationthe mixture was concentrated
3. customThe residue was partitioned between 300 mL of EA and 300 mL of aq. sat. NH4Cl
4. washThe organic layer was washed with brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customto get crude product which
9. filtrationfiltered
10. customThe collected solid was dried in air

ORD record

ord-b4eb32e1f20a40b28166e7ceb70a9d5a

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09447106B2