Trifluoroacetic acid → 1-(2-Fluoro-3-hydroxy-6-nitrophenyl)propan-2-one

To a solution of tert-butyl 2-(2-fluoro-3-hydroxy-6-nitrophenyl)-3-oxobutanoate (7.89 g) in dichloromethane was added trifluoroacetic acid (11.2 g) and the mixture stirred at ambient temperature for 20 hours. The mixture was concentrated to a thick paste and toluene (14 ml) added and the mixture distilled on a rotary evaporator (77 mbar, bath 40° C.). Further toluene (14 ml) was added and the mixture distilled. Sodium hydroxide (7.4% w/w, 20 ml) was added and the lower aqueous layer separated and washed with toluene (18 ml). The aqueous layer was diluted with water (20 ml) and warmed to 40° C. Acetic acid (13 ml) was added followed by sulphuric acid (20% w/w, 20 ml). The mixture was cooled to 0° C. and further water (43 ml) added. The mixture was cooled to −5° C. and left overnight. The solid was filtered and washed with water (24 ml). The solid was dried in a vacuum oven to give 1-(2-fluoro-3-hydroxy-6-nitrophenyl)-propan-2-one (1.65 g, 30.7%).

1. concentrationThe mixture was concentrated to a thick paste and toluene (14 ml)
2. additionadded
3. distillationthe mixture distilled on a rotary evaporator (77 mbar, bath 40° C.)
4. additionFurther toluene (14 ml) was added
5. distillationthe mixture distilled
6. additionSodium hydroxide (7.4% w/w, 20 ml) was added
7. customthe lower aqueous layer separated
8. washwashed with toluene (18 ml)
9. additionThe aqueous layer was diluted with water (20 ml)
10. temperaturewarmed to 40° C
11. additionAcetic acid (13 ml) was added
12. temperatureThe mixture was cooled to 0° C.
13. additionfurther water (43 ml) added
14. temperatureThe mixture was cooled to −5° C.
15. waitleft overnight
16. filtrationThe solid was filtered
17. washwashed with water (24 ml)
18. customThe solid was dried in a vacuum oven

ORD record

ord-de444a36f9eb4ce3b0a3fc163437e482

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08754240B2