Sodium Nitrite → (2-Fluoro-4-methoxyphenyl)hydrazine

Temperature

0 °C

To a vigorously stirred suspension of 2-fluoro-4-methoxyaniline hydrochloride (665 mg, 3.7 mmol) in conc. HCl (5.5 mL) cooled to 0° C. was added a cold solution of NaNO2 (312 mg, 4.5 mmol) in H2O (1 mL). The mixture was stirred at 0° C. for 90 min. A cold solution of SnCl2-2H2O (3.4 g, 15.0 mmol) in conc. HCl (5.5 mL) was then added slowly to the solution of diazonium salt. The reaction was allowed to warm to room temperature, stirred for 30 min and the reaction was filtered. The collected precipitate was washed on the filter with several large portions of ether and dried under vacuum. The solid was dissolved in DCM and washed saturated NaHCO3, extracted and dried using a phase separator. Evaporation gave (2-fluoro-4-methoxyphenyl)hydrazine (220 mg 38%), which was used in the next step without further purification. The procedure was adapted from J. Med. Chem. 2000, 43, 4701.

1. temperatureto warm to room temperature
2. stirringstirred for 30 min
3. filtrationthe reaction was filtered
4. washThe collected precipitate was washed on the
5. filtrationfilter with several large portions of ether
6. customdried under vacuum
7. dissolutionThe solid was dissolved in DCM
8. washwashed saturated NaHCO3
9. extractionextracted
10. customdried
11. customEvaporation

ORD record

ord-a34c36d0eb514496a3dff4a096592d90

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08653112B2