Water → 2-chloro-9-hydroxy-9-trifluoromethyl-9H-fluorene-4-carboxylic acid

To a mixture of 2-chloro-4-methyl-9-trifluoromethyl-9H-fluoren-9-ol (2.987 g), pyridine (6 ml) and water (24 ml) was added potassium permanganate (7.902 g) at 100° C., and the mixture was stirred for 2 hr. To this mixture were added further potassium permanganate (4.70 g) and pyridine (6 ml) and the mixture was stirred at 100° C. for 2 hr. Potassium permanganate (4.70 g) was further added and the mixture was stirred at 100° C. for 2 hr. This operation was repeated twice. The reaction mixture was cooled to room temperature, and the insoluble material was filtered off and washed with water (50 ml). The filtrate was adjusted to pH 1 with 6N hydrochloric acid, and extracted with ethyl acetate (200 ml). The organic layer was successively washed with water and saturated brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure and the obtained residue was treated with hexane/ethyl acetate mixed solution (hexane:ethyl acetate=9:1) (30 ml). This slurry was filtered, and the obtained solid was dried to give the title compound (2.509 g, 76%).

1. stirringthe mixture was stirred at 100° C. for 2 hr
2. stirringthe mixture was stirred at 100° C. for 2 hr
3. filtrationthe insoluble material was filtered off
4. washwashed with water (50 ml)
5. extractionextracted with ethyl acetate (200 ml)
6. washThe organic layer was successively washed with water and saturated brine
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationThe filtrate was concentrated under reduced pressure
10. additionthe obtained residue was treated with hexane/ethyl acetate mixed solution (hexane:ethyl acetate=9:1) (30 ml)
11. filtrationThis slurry was filtered
12. customthe obtained solid was dried

ORD record

ord-cd30149b126541a09af0cd26b25293a1

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08871934B2