Hydrochloric Acid → 7-Fluoro-2,3-dihydro-1h-indol-2-one

HRID 2355778Notes

Reaction equation

HRID 2355778 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:10]=1[NH:9][C:8](=[O:11])[C:7]2=O.NN.O.Cl>C(O)CO>[F:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:10]=1[NH:9][C:8](=[O:11])[CH2:7]2

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 9321HydrazineHCID 5864187-Fluoroisatin

Product 1

HCID 37343717-Fluoro-2,3-dihydro-1h-indol-2-oneYield 83%

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Conditions

Temperature
120 °C

Procedure

To a mixture of 7-fluoro-1H-indole-2,3-dione (100 g, 0.606 mol) in ethylene glycol (500 mL) was added an aqueous hydrazine solution (54% wt, 73 g, 1.21 mol) dropwise over 30 minutes. The mixture was heated to 120° C. and stirred for 6 hours. The mixture was cooled to room temperature and water (500 mL) was added. Concentrated hydrochloric acid (HCl; 60 mL) was added, the mixture was warmed to about 35 to about 40° C., and the mixture was stirred for 1 hour. The mixture was then cooled to about 0 to about 5° C. The solid compound was filtered, washed with cold water and dried at 55° C. under vacuum to give an off-white solid (76 g) in 83% yield with 96% HPLC purity.

Workup

  1. temperatureThe mixture was cooled to room temperature
  2. temperaturethe mixture was warmed to about 35 to about 40° C.
  3. stirringthe mixture was stirred for 1 hour
  4. temperatureThe mixture was then cooled to about 0 to about 5° C
  5. filtrationThe solid compound was filtered
  6. washwashed with cold water
  7. customdried at 55° C. under vacuum

Sources & evidence

ORD record
ord-f4ebf23b7d43407d9524da119a3bc0e2
Source dataset
uspto-grants-2010_07
Patent number
US07754895B2

Reaction notes

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