Trifluoroacetic acid → 2-(3,3-Dimethyl-indan-5-yl)-5-methyl-2,4-dihydro-pyrazol-3-one

Temperature

100 °C

Di-tert-butyl 1-(3,3-dimethyl-2,3-dihydro-1H-inden-5-yl)hydrazine-1,2-dicarboxylate 8h (2.70 g, 7.18 mmol) was dissolved in 100 mL of acetic acid followed by addition of 20 mL of trifluoroacetic acid. After the mixture was reacted at room temperature for 2 hours, ethyl acetoacetate (0.98 g, 7.54 mmol) was added. Then the mixture was heated to 100° C. and reacted for 2 hours. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was cooled to room temperature and concentrated under reduced pressure to remove acetic acid. The reaction mixture was neutralized by saturated aqueous sodium bicarbonate. Then the mixture was extracted with ethyl acetate. The combined organic extracts were washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound 2-(3,3-dimethyl-indan-5-yl)-5-methyl-2,4-dihydro-pyrazol-3-one 8i (1.0 g, yield 47.7%) as a light brown solid.

1. customAfter the mixture was reacted at room temperature for 2 hours
2. customreacted for 2 hours
3. temperatureThe mixture was cooled to room temperature
4. concentrationconcentrated under reduced pressure
5. customto remove acetic acid
6. extractionThen the mixture was extracted with ethyl acetate
7. washThe combined organic extracts were washed with saturated brine
8. dry with materialdried over anhydrous sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe resulting residue was purified by silica gel column chromatography

ORD record

ord-611d971879bd4fb59b46e2c6e0c6c95f

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367710B2