Hydrochloric Acid → 2-(3,5-Difluoro-4-nitrophenyl)acetic acid

1,1-dimethylethyl (3,5-difluoro-4-nitrophenyl)acetate (150 g) and 4M HCl in 1,4-dioxane (1150 ml) was stirred for 18 h at about 25° C. Nitrogen was bubbled through the mixture to remove excess HCl over 7 hours, then the mixture was concentrated. Toluene (300 ml) was distilled off then the residue was stirred with hexane (300 ml) for 10 minutes. The hexane was decanted off, and the residue stirred with hexane (150 ml) for 10 minutes, then the hexane was decanted off. The residue was stirred with toluene (450 ml) for 2 hours at around 25° C. The solid was filtered and washed with 1:1 toluene/hexane (300 ml), then dried under vacuum to give the title compound as a brown fine powder (41.5 g).

1. customNitrogen was bubbled through the mixture
2. customto remove excess HCl over 7 hours
3. concentrationthe mixture was concentrated
4. distillationToluene (300 ml) was distilled off
5. customThe hexane was decanted off
6. stirringthe residue stirred with hexane (150 ml) for 10 minutes
7. customthe hexane was decanted off
8. stirringThe residue was stirred with toluene (450 ml) for 2 hours at around 25° C
9. filtrationThe solid was filtered
10. washwashed with 1:1 toluene/hexane (300 ml)
11. customdried under vacuum

ORD record

ord-27079f18315f46d187f8274d2782946e

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08481566B2