(+-)-2-Butanol → 5-Bromo-2-hydrazinopyridine

A 12 L three-necked round-bottomed flask equipped with a mechanical stirrer and a condenser, connected on top with a nitrogen bubbler and a thermometer, was charged with 2,5-dibromopyridine (442 g, 1.87 moles), hydrazine hydrate (55% wt., 1057 ml, 18.7 moles), poly(ethylene glycol) (average Mn about 300, 1.87 L), 2-butanol (373 ml) and water (1.87 L). The mixture was heated at reflux for 29 hours. The heating source was removed and the mixture was stirred for an additional 20 hours. To the resulting slurry, cold water (2.2 L) was added. The slurry was stirred for an additional 30 minutes and filtered. The cake was washed with cold water (3×200 ml) and dried in a vacuum-oven (40° C.) for 48 hours. The title compound was obtained as off-white flakes (305 g, yield 87%).

1. customA 12 L three-necked round-bottomed flask equipped with a mechanical stirrer and a condenser
2. temperatureThe mixture was heated
3. temperatureat reflux for 29 hours
4. customThe heating source was removed
5. additionTo the resulting slurry, cold water (2.2 L) was added
6. stirringThe slurry was stirred for an additional 30 minutes
7. filtrationfiltered
8. washThe cake was washed with cold water (3×200 ml)
9. customdried in a vacuum-oven (40° C.) for 48 hours

ORD record

ord-5c0b5f1c8eb1442b9a9841b96c00b7b9

Source dataset

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07259171B2