Reaction equation
C[O:2][C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([N+:11]([O-])=O)[C:6]=1[CH:14](C(OC)=O)[C:15]([O:17]C)=O)=[O:4]>Cl>[C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:6]=1[CH2:14][C:15](=[O:17])[NH:11]2)([OH:2])=[O:4]Participants
3
Reactant 1
Product 1
Reagents, catalysts & solvents 1
Procedure
Dimethyl 2-methoxycarbonyl-6-nitrophenylmalonate (3.0 g) was refluxed in 50 mL of 6 N hydrochloric acid overnight. The mixture was concentrated to dryness and refluxed for 2 hours with 1.1 g of tin(II) chloride in 20 mL of ethanol. The mixture was filtered through Celite, concentrated and chromatographed on silica gel (ethyl acetate:hexane:acetic acid) to give 0.65 g (37% yield) of 4-carboxy-2-oxindole as a white solid.
Workup
- concentrationThe mixture was concentrated to dryness
- temperaturerefluxed for 2 hours with 1.1 g of tin(II) chloride in 20 mL of ethanol
- filtrationThe mixture was filtered through Celite
- concentrationconcentrated
- customchromatographed on silica gel (ethyl acetate:hexane:acetic acid)
Sources & evidence
- ORD record
- ord-ab4f5179f5b64220b2b28e265ead3b45
- Source dataset
- uspto-grants-2000_10
- Patent number
- US06130238
Linked notes
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