Triethylamine → tert-Butyl 3-amino-5-nitro-1H-indazole-1-carboxylate

HRID 1823907Notes

Reaction equation

HRID 1823907 reaction equation
CN(C1C=CC=CN=1)C.[N+:10]([C:13]1[CH:14]=[C:15]2[C:19](=[CH:20][CH:21]=1)[NH:18][N:17]=[C:16]2[NH2:22])([O-:12])=[O:11].[C:23]([O:27][C:28](OC([O-])=O)=[O:29])([CH3:26])([CH3:25])[CH3:24].C(N(CC)CC)C>C1COCC1>[C:23]([O:27][C:28]([N:18]1[C:19]2[C:15](=[CH:14][C:13]([N+:10]([O-:12])=[O:11])=[CH:21][CH:20]=2)[C:16]([NH2:22])=[N:17]1)=[O:29])([CH3:26])([CH3:25])[CH3:24]

Participants

6

Reactant 4

HCID 8471TriethylamineHCID 218852-DimethylaminopyridineHCID 31366553-Amino-5-nitroindazoleHCID 22064466Tert-butyldicarbonate

Product 1

HCID 23571039tert-Butyl 3-amino-5-nitro-1H-indazole-1-carboxylateYield 50%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Dimethylaminopyridine (4 g, 36 mmol) was added to a solution of 5-nitro-1H-indazol-3-ylamine (32.2 g, 181 mmol), tert-butyldicarbonate (39.4 g, 181 mmol) and triethylamine (25 mL, 181 mmol) in THF (1 L) at room temperature under nitrogen. After stirring for 30 minutes, the reaction mixture was concentrated and the residue partitioned between EtOAc and saturated ammonium chloride solution. The layers were separated and the organic phase washed with brine, dried (MgSO4), and concentrated to an orange solid. Recrystallisation from ethyl acetate provided the title product as a yellow solid (25 g, 50%). 1H NMR (400 MHz, DMSO) 1.60 (9H, s), 6.75 (2H, brs), 8.10 (1H, d), 8.36 (1H, d), 8.96 (1H, s); MS (ES−) m/e=277.

Workup

  1. concentrationthe reaction mixture was concentrated
  2. customthe residue partitioned between EtOAc and saturated ammonium chloride solution
  3. customThe layers were separated
  4. washthe organic phase washed with brine
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated to an orange solid
  7. customRecrystallisation from ethyl acetate

Sources & evidence

ORD record
ord-e972411ee5eb4d5ea99d6088f62f22f1
Source dataset
uspto-grants-2006_05
Patent number
US07041687B2

Reaction notes

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