tert-Butyl 5-Nitro-1H-indazole-1-carboxylate → 1,1-Dimethylethyl 5-amino-1H-indazole-1-carboxylate

HRID 225778Notes

Reaction equation

HRID 225778 reaction equation
[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][C:13]([N+:17]([O-])=O)=[CH:14][CH:15]=2)[CH:10]=[N:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]>[Pd].CCO.CCOC(C)=O.C(Cl)Cl>[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][C:13]([NH2:17])=[CH:14][CH:15]=2)[CH:10]=[N:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

6

Reactant 1

HCID 11499917tert-Butyl 5-Nitro-1H-indazole-1-carboxylate

Product 1

HCID 198005561,1-Dimethylethyl 5-amino-1H-indazole-1-carboxylateYield 95%

Reagents, catalysts & solvents 4

HCID 23938PalladiumCatalystHCID 702EthanolSolvent2×HCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

Palladium on carbon (780 mg) was placed under an inert atmosphere and suspended in EtOH (15 mL). A solution of 5-nitroindazole-1-carboxylic acid tert-butyl ester (7.78 g, 29.5) in EtOH (100 mL) and EtOAc (100 mL) was added. The reaction mixture was placed under H2 atmosphere (1 Atm pressure) and stirred overnight. The resulting mixture was filtered through a pad of Celite®. The filtrate was concentrated under reduced pressure to yield a greenish foamy solid. The crude product was dissolved in CH2Cl2 and purified by Biotage Flash 40M (gradient from 30% to 50% EtOAc/hex) to give the title compound (6.55 g, 95%) as a white solid: TLC (50%EtOAc/hex), Rf=0.41; ES-LCMS (rel abundance) m/z 234 (MH+, 66%).

Workup

  1. filtrationThe resulting mixture was filtered through a pad of Celite®
  2. concentrationThe filtrate was concentrated under reduced pressure
  3. customto yield a greenish foamy solid
  4. custompurified by Biotage Flash 40M (gradient from 30% to 50% EtOAc/hex)

Sources & evidence

ORD record
ord-d10bb0055b8f46afbfb6f353f92cd89d
Source dataset
uspto-grants-2009_07
Patent number
US07557129B2

Reaction notes

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