Hydrochloric Acid → 4-Amino-3-fluorophenol

The 14 g (0.09 mol) of 3-fluoro-4-nitrophenol from above was combined with 55 mL (0.66 mol) of concentrated HCl, 55 mL of H2O, and 0.5 mL of octanol and stirred mechanically. To this mixture was added 33 g (0.28 mol) of mossy tin and the mixture was heated on a steam bath to initiate the reaction. After the reaction had subsided (8-10 minutes), 92 mL of concentrated HCl in 160 mL of water was added. The reaction was stirred on the steam bath for 1/2 hour and filtered hot. The filtrate was cooled and made basic with solid sodium bicarbonate. The resulting salts were filtered off and washed with ethyl acetate. The filtrate was extracted three times with ethyl acetate; all of the ethyl acetate extracts were combined, washed twice with saturated sodium chloride solution, and dried over magnesium sulfate. The solvent was stripped in vacuo and the resulting residue dissolved and stripped twice with toluene then ethanol then acetonitrile. The solid residue was triturated in hexane, filtered and washed to yield 10.9 g (96%) of 4-amino-3-fluorophenol, mp 138°-140° C.

1. temperaturethe mixture was heated on a steam bath
2. customthe reaction
3. additionwas added
4. stirringThe reaction was stirred on the steam bath for 1/2 hour
5. filtrationfiltered hot
6. temperatureThe filtrate was cooled
7. filtrationThe resulting salts were filtered off
8. washwashed with ethyl acetate
9. extractionThe filtrate was extracted three times with ethyl acetate
10. washwashed twice with saturated sodium chloride solution
11. dry with materialdried over magnesium sulfate
12. dissolutionthe resulting residue dissolved
13. customThe solid residue was triturated in hexane
14. filtrationfiltered
15. washwashed

ORD record

ord-71e8e31c8f8041eda2365fa9a3a690e1

Source dataset

uspto-grants-1989_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04835180