Hydrazine hydrate (1:1) → 1-benzyl-1,3-dihydro-2H-indol-2-one

HRID 2281760Notes

Reaction equation

HRID 2281760 reaction equation
[CH2:1]([N:8]1[C:18]2[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=2)[C:11](=O)[C:9]1=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O.NN>CCOCC.CCCCC>[CH2:1]([N:8]1[C:18]2[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=2)[CH2:11][C:9]1=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 2647341-Benzylisatin

Product 1

HCID 117908211-benzyl-1,3-dihydro-2H-indol-2-oneYield 78.2%

Reagents, catalysts & solvents 1

HCID 21877078Diethylether pentaneSolvent

Conditions

Temperature
125 °C

Procedure

N-benzylisatin (13.0 g, 55 mmol) was mixed with hydrazine hydrate (60 mL) and placed in an oil bath. The mixture was heated in stages to 125° C., becoming first a green sludge, then yellow with clumps of a sticky solid. After a total of 5 h at 125° C., the mixture was cooled and extracted with EtOAc (2×100 mL). The combined organic portions were washed twice with 1.0 M aq. H2SO4, and once each with half-saturated brine then brine, dried over MgSO4, filtered and concentrated to afford a pale yellow solid. Re-precipitation from ether/pentane gave the title compound as an off-white solid (9.6 g, 75%). Spectral data matches literature values (C. Martin and E. M. Carreira, J. Am. Chem. Soc., 2005, 127, 11505-11515).

Workup

  1. customplaced in an oil bath
  2. temperatureAfter a total of 5 h at 125° C., the mixture was cooled
  3. extractionextracted with EtOAc (2×100 mL)
  4. washThe combined organic portions were washed twice with 1.0 M aq. H2SO4
  5. dry with materialonce each with half-saturated brine then brine, dried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto afford a pale yellow solid

Sources & evidence

ORD record
ord-b129c8b94238443cb9d2e02d618645b7
Source dataset
uspto-grants-2015_09
Patent number
US09139563B2

Reaction notes

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