Hydrochloric Acid → 3-Hydrazinylpyridine dihydrochloride

Temperature

-5 °C

To a mixture of 3-aminopyridine (9.41 g, 100 mmol) and conc. hydrochloric acid (100 mL) which was cooled to a temperature of lower than −5° C., a solution of sodium nitrite (7.20 g, 105 mmol) in water (60 mL) was added dropwise. Subsequently, a solution of tin chloride (II) (56.9 g, 300 mmol) in conc. hydrochloric acid (50 mL) was added dropwise thereto carefully so that the temperature of the solution did not exceed −5° C. The solution was stirred at a temperature of lower than −5° C. for additional 3 hours, and the resulting crystals were collected by filtration. The crystals were washed with diethylether/methanol and air dried to give the title compound (15.6 g, 85% yield). The compound was used in the following process without further purification.

1. customdid not exceed −5° C
2. filtrationthe resulting crystals were collected by filtration
3. washThe crystals were washed with diethylether/methanol and air
4. customdried

ORD record

ord-35c00f7ac27d4c6fbc10fb662dbf4403

Source dataset

uspto-grants-2005_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06949648B2