Sodium → 4-Chloro-1,3-dihydro-2H-indol-2-one
Reaction equation
[Na].[Cl:2][C:3]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:4]=1[C:5](=NN)[C:6](=[O:12])[NH:7]2>C(O)C>[Cl:2][C:3]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:4]=1[CH2:5][C:6](=[O:12])[NH:7]2Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a stirred solution of 22 g of sodium in 450 ml of anhydrous ethanol was added, portionwise, 43.5 g of 4-chloro-3-hydrazono-2-oxindole, and the resulting solution was heated under reflux for 30 minutes. The cooled solution was then concentrated to a gum, which was dissolved in 400 ml of water and decolorized using activated carbon. The resulting solution was poured onto a mixture of 1 liter of water and 45 ml of concentrated hydrochloric acid. The precipitate which formed was recovered by filtration, dried and recrystallized from ethanol, giving 22.4 g of 4-chloro-2-oxindole, mp 216°-218° C. (dec).
Workup
- temperatureunder reflux for 30 minutes
- concentrationThe cooled solution was then concentrated to a gum, which
- dissolutionwas dissolved in 400 ml of water
- additionThe resulting solution was poured onto a mixture of 1 liter of water and 45 ml of concentrated hydrochloric acid
- customThe precipitate which formed
- filtrationwas recovered by filtration
- customdried
- customrecrystallized from ethanol
Sources & evidence
- ORD record
- ord-ac4aebe4a8a6474bb53b534329589c0f
- Source dataset
- uspto-grants-1987_03
- Patent number
- US04652658
Reaction notes
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