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

HRID 658443Notes

Reaction equation

HRID 658443 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 give 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 get 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 get a greenish foamy solid
  4. custompurified by Biotage Flash 40M (gradient from 30% to 50% EtOAc/hex)

Sources & evidence

ORD record
ord-b2141363ba6f44a89d37eefc6b307f7f
Source dataset
uspto-grants-2011_12
Patent number
US08076488B2

Reaction notes

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