Hydrazine hydrate (1:1) → 2-Hydrazinyl-6-methylpyridine

Temperature

120 °C

A mixture of 2-bromo-6-methyl-pyridine (602.10 g) and hydrazine hydrate (1570 ml) was refluxed at 120° C. for 6 hours, and then stirred at room temperature for about 48 hours. The solid separated was extracted with diethylether (3×1.5 L) and the combined ether extracts were washed with brine, dried over Na2SO4, filtered and concentrated (˜430 g). The residue was stirred in a mixture of ether (200 ml) and hexane (1.5 L), filtered and washed with 5% diethylether in hexane to give a pale yellow solid (sticky). The solid was vacuum distilled at 106-113° C./2 mm, which solidified instantly. The solid was then dissolved in 2 L of diethylether and precipitated by adding 2 L of hexane, filtered and vacuum dried to give 1-(6-methylpyridin-2-yl)hydrazine as white solid (240 g).

1. customThe solid separated
2. extractionwas extracted with diethylether (3×1.5 L)
3. washthe combined ether extracts were washed with brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated (˜430 g)
7. stirringThe residue was stirred in a mixture of ether (200 ml) and hexane (1.5 L)
8. filtrationfiltered
9. washwashed with 5% diethylether in hexane
10. customto give a pale yellow solid (sticky)
11. distillationdistilled at 106-113° C./2 mm, which
12. dissolutionThe solid was then dissolved in 2 L of diethylether
13. customprecipitated
14. additionby adding 2 L of hexane
15. filtrationfiltered
16. customvacuum dried

ORD record

ord-5aa0512341754071a8a1b4d17b149859

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09260450B2