1-(3-fluorobenzyl)-5-nitro-1H-indazole → 1-(3-Fluorobenzyl)-1H-indazol-5-amine

HRID 2353818Notes

Reaction equation

HRID 2353818 reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[C:16]([F:20])[CH:15]=1)[N:8]=[CH:7]2)([O-])=O>C(O)(=O)C.CCOC(C)=O.[Fe]>[NH2:1][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[C:16]([F:20])[CH:15]=1)[N:8]=[CH:7]2

Participants

5

Reactant 1

HCID 219664901-(3-fluorobenzyl)-5-nitro-1H-indazole

Product 1

HCID 71470731-(3-Fluorobenzyl)-1H-indazol-5-amineYield 76%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 176Acetic AcidSolventHCID 8857Ethyl AcetateSolvent

Procedure

5-nitro-1-N-(3-fluorobenzyl)indazole (7.9 g, 29.1 mmol, 1 equiv) and iron (8.13 g, 145.6 mmol, 5 equiv) were mixed in 200 mL acetic acid and 50 mL EtOAc, and were stirred at rt for 36 h. The reaction mixture was filtered through a pad of Celite®. The filtrate was concentrated in vacuo to 10 mL volume. The contents were diluted with water (10 mL) and neutralized with saturated Na2CO3 solution. The solution was extracted with EtOAc (3×500 mL), the combined organic layers dried over MgSO4, filtered, and concentrated in vacuo. The resulting crude material was purified by column chromatography eluting with hexanes/EtOAC (4:1 to 3:1) to give 5-amino-1-N-(3-fluorobenzyl)indazole (5.32 g, 76%) as a light brown solid. 1H-NMR (DMSO-d6) δ 7.72 (s, 1H), 7.22-7.36 (m, 2H), 6.87-7.05 (m, 3H), 6.70-6.77 (m, 2H), 5.48 (s, 2H), 4.78 (br s, 2H); LCMS RT=1.66 min; [M+H]+=242.2.

Workup

  1. filtrationThe reaction mixture was filtered through a pad of Celite®
  2. concentrationThe filtrate was concentrated in vacuo to 10 mL volume
  3. additionThe contents were diluted with water (10 mL)
  4. extractionThe solution was extracted with EtOAc (3×500 mL)
  5. dry with materialthe combined organic layers dried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe resulting crude material was purified by column chromatography
  9. washeluting with hexanes/EtOAC (4:1 to 3:1)

Sources & evidence

ORD record
ord-48f40a47cb79440fb7f31ea12da4fafb
Source dataset
uspto-grants-2010_07
Patent number
US07750017B2

Reaction notes

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