Sodium borohydride → methyl 4-amino-1H-indazole-1-carboxylate

HRID 1791328Notes

Reaction equation

HRID 1791328 reaction equation
[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[N:7][N:8]2[C:13]([O:15][CH3:16])=[O:14])([O-])=O.[BH4-].[Na+]>C(O)C>[NH2:1][C:4]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[N:7][N:8]2[C:13]([O:15][CH3:16])=[O:14]

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 22032604methyl 4-nitro-1H-indazole-1-carboxylate

Product 1

HCID 22032652methyl 4-amino-1H-indazole-1-carboxylateYield 83.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The product of Example 90A (1.66 g, 7.5 mmol) in ethanol (20 mL) was treated with BiCl3 (8.2 g, 2.6 mmol) followed by the addition of NaBH4 (1.13 g, 30.5 mmol). The reaction mixture was stirred at room temperature for 20 minutes, filtered through Celite, and the filtrate was evaporated under reduced pressure. The residue was partitioned between ethyl acetate/dilute NaHCO3 solution. The organic phase was separated, dried over MgSO4, filtered and the filtrate concentrated under reduced pressure to provide the title compound (1.2 g). 1H NMR (300 MHz, DMSO-d6) δ 6.1 (s, 2H), 6.41 (dd, 1H), 7.21 (m, 2H), 8.42 (s, 1H).

Workup

  1. filtrationfiltered through Celite
  2. customthe filtrate was evaporated under reduced pressure
  3. customThe residue was partitioned between ethyl acetate/dilute NaHCO3 solution
  4. customThe organic phase was separated
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationthe filtrate concentrated under reduced pressure

Sources & evidence

ORD record
ord-76f351b7aaeb48c2a08b8b641d36c13e
Source dataset
uspto-grants-2006_07
Patent number
US07074805B2

Reaction notes

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