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

Temperature

0 °C

2-Bromo-6-fluoroaniline (2.0 g, 11 mmol) was dissolved in hydrochloric acid (7.0 mL, 12 N aqueous, 84 mmol, 8 equiv) and cooled to 0° C. An aqueous solution (10 mL) of sodium nitrite (0.80 g, 12 mmol, 1.1 equiv) was added dropwise over 30 minutes via additional 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(II) chloride dihydrate (7.1 g, 32 mmol, 3 equiv) was then added to the mixture over 45 minutes via additional funnel and the mixture was stirred for an additional 1 hour at 0° C. To the mixture, sodium hydroxide (30 mL, 1 M aqueous) was added slowly until basic by pH paper. 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 residue was taken up in diethyl ether and treated with gaseous hydrochloric acid. The solid was filtered and washed with diethyl ether, 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. additiontreated with gaseous hydrochloric acid
8. filtrationThe solid was filtered
9. washwashed with diethyl ether

ORD record

ord-8c2649a3427444b19361631e0b7e6c13

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08895580B2