Hydrochloric Acid → (2-Bromo-6-fluorophenyl)hydrazine hydrochloride

Temperature

0 °C

2-Bromo-6-fluoroaniline (2.0 g, 10 mmol) was dissolved in hydrochloric acid (7.0 mL, 12 N aqueous, 8.0 equiv) and cooled to 0° C. An aqueous solution (10 mL) of sodium nitrite (0.80 g, 11 mmol, 1.1 equiv) was added dropwise over 30 minutes via addition funnel and the mixture was stirred for an additional 30 minutes at 0° C. A hydrochloric acid solution (10 mL, 12 N aqueous) of stannous chloride (7.1 g, 31 mmol, 3.0 equiv) was then added to the mixture over 45 minutes via addition funnel and the mixture was stirred for an additional 1 hour at 0° C. To the mixture, sodium hydroxide (30 mL, 1 N aqueous) was added slowly until basic (pH>8). The mixture was warmed to ambient temperature, poured into sodium hydroxide (50 mL, 25% aqueous) and the aqueous layer was extracted with diethyl ether (3×250 mL). The combined organic extracts were dried with sodium sulfate, filtered and partially concentrated in vacuo. The mixture was diluted with diethyl ether (200 mL) and treated with gaseous hydrochloric acid until saturated, resulting in a white precipitate, which was filtered and washed with diethyl ether (2×50 mL), providing the titled compound as a white solid.

1. stirringthe mixture was stirred for an additional 1 hour at 0° C
2. temperatureThe mixture was warmed to ambient temperature
3. extractionthe aqueous layer was extracted with diethyl ether (3×250 mL)
4. dry with materialThe combined organic extracts were dried with sodium sulfate
5. filtrationfiltered
6. concentrationpartially concentrated in vacuo
7. additionThe mixture was diluted with diethyl ether (200 mL)
8. additiontreated with gaseous hydrochloric acid until saturated,
9. customresulting in a white precipitate, which
10. filtrationwas filtered
11. washwashed with diethyl ether (2×50 mL)

ORD record

ord-60cdd1aed1c543b8a16e9bf4177c76de

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08486946B2