Sulfuric Acid → 5-(1-phenyl-1H-pyrazol-5-yl)indolin-2-one

To a solution of 5-(3,3-diethoxyprop-1-ynyl)indolin-2-one (100 mg, 0.39 mmol) in acetonitrile (5 ml) were added phenyl hydrazine (38 μL, 0.38 mmol) and sulfuric acid (52 μL, 0.98 mmol), and the mixture was stirred for 3 h at room temperature, then the mixture was stirred for 2 h at 50° C. The reaction mixture was poured into water (50 mL), and the resulting precipitate was filtered and dried. The precipitated was dissolved in acetonitrile (5 mL), then water (52 μL, 3.9 mmol) and sulfuric acid (93 μL, 1.75 mmol) were added. The mixture was heated at 80 C for 4 h. The mixture was cooled to room temperature, and then neutralized with sat. NaHCO3. The mixture was extracted with CHCl3/EtOAc 3 times. The combined organic extracts were washed with sat. NaCl, dried over Na2SO4, and evaporated in vacuo. The residue purified by column chromatography (EtOAc/n-hexane) to give the title compound as a brown solid (44 mg, 41%).

1. stirringthe mixture was stirred for 2 h at 50° C
2. filtrationthe resulting precipitate was filtered
3. customdried
4. dissolutionThe precipitated was dissolved in acetonitrile (5 mL)
5. temperatureThe mixture was heated at 80 C for 4 h
6. temperatureThe mixture was cooled to room temperature
7. extractionThe mixture was extracted with CHCl3/EtOAc 3 times
8. washThe combined organic extracts were washed with sat. NaCl
9. dry with materialdried over Na2SO4
10. customevaporated in vacuo
11. customThe residue purified by column chromatography (EtOAc/n-hexane)

ORD record

ord-789a5e75e1a8482cb753c94eb7d01643

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09227962B2