Hydrazine → 3-Bromo-2-hydrazinopyridine

To 3-bromo-2-chloropyridine (1-3) (12.5 g, 65 mmol) in THF (100 mL) was added hydrazine (10.4 g, 10.2 mL, 325 mmol). The mixture was heated to reflux and stirred vigorously for 16 h. An additional portion of hydrazine (5.1 g, 5.0 mL, 159 mmol) was added and the reaction was heated for another 24 h. After cooling, the mixture was concentrated in vacuo, suspended in water (50 mL), and extracted with EtOAc (1×350 mL, 1×50 mL). Combined organic layers were washed with brine (50 mL), dried over MgSO4, filtered, and concentrated in vacuo. The resulting crude product (1-4) was used in the subsequent step without further purification. LC/MS: m/z (M+H)=187.9.

1. temperatureThe mixture was heated
2. temperatureto reflux
3. temperaturethe reaction was heated for another 24 h
4. temperatureAfter cooling
5. concentrationthe mixture was concentrated in vacuo
6. extractionextracted with EtOAc (1×350 mL, 1×50 mL)
7. washCombined organic layers were washed with brine (50 mL)
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe resulting crude product (1-4) was used in the subsequent step without further purification

ORD record

ord-4ada39427e7349149e67575108099f2f

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266881B2