Hydrazine hydrate (1:1) → 5-Bromo-3-fluoro-2-hydrazinylpyridine

To a solution of 5-bromo-2,3-difluoropyridine (15 g, 77 mmol)) in EtOH (250 ml) was added hydrazine hydrate (19.36 g, 387 mmol), the mixture was heated to reflux and stirred overnight (16 hr). The solvent of the reaction mixture was evaporated about half under reduced pressure, then cooling in an ice bath there precipitation was occurred, filtered and washed the product with a minimum of EtOH and water, dried in vacuum to obtain pure desired product as white powder (15 g, yield 94%). LCMS (method A): [M+H]+=206.0, 208.0, tR=1.01 min.

1. temperaturethe mixture was heated
2. temperatureto reflux
3. customThe solvent of the reaction mixture was evaporated about half under reduced pressure
4. temperaturecooling in an ice bath
5. customthere precipitation
6. filtrationfiltered
7. washwashed the product with a minimum of EtOH and water
8. customdried in vacuum

ORD-Eintrag

ord-15fd6bafa7bb42848e26d1c8772d79c4

Quelldatensatz

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09062045B2