Nitric Acid → 1-(4-Fluoro-5-nitroindolin-1-yl)ethan-1-one

HRID 506180Notes

Reaction equation

HRID 506180 reaction equation
[F:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:3]=1[CH2:4][CH2:5][N:6]2[C:11](=[O:13])[CH3:12].FC1C=CC=C2C=1C=CN2.OS(O)(=O)=O.[N+:29]([O-])([OH:31])=[O:30]>C(O)(=O)C>[F:1][C:2]1[C:10]([N+:29]([O-:31])=[O:30])=[CH:9][CH:8]=[C:7]2[C:3]=1[CH2:4][CH2:5][N:6]2[C:11](=[O:13])[CH3:12]

Participants

6

Reactant 4

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 27745024-FluoroindoleHCID 669150381-Acetyl-4-fluoroindoline

Product 1

HCID 669150301-(4-Fluoro-5-nitroindolin-1-yl)ethan-1-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Treatment of 1-(4-fluoro-2,3-dihydro-indol-1-yl)-ethanone, prepared from 4-fluoroindole (See e.g., EP 0645385A1), with concentrated H2SO4 and fuming HNO3 in glacial acetic acid gave 1-(4-fluoro-5-nitro-2,3-dihydro-indol-1-yl)-ethanone. Deprotection of the acetyl group with Na2S in aqueous ethanol provided 4-fluoro-5-nitro-2,3-dihydro-1H-indole, which was treated with 2,3-dicyano-5,6-dichloro-parabenzoquinone (DDQ) to provide 4-fluoro-5-nitroindole. A subsequent hydrogenation over Pd/C gave 5-amino-4-fluoroindole.

Sources & evidence

ORD record
ord-2e3d76ae270d4a529e4439bf1d4489a3
Source dataset
uspto-grants-2010_08
Patent number
US07781591B2

Reaction notes

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