5-Fluoro-2-methyl-4-nitroaniline → 6-Fluoro-5-nitro-1H-indazole

HRID 227716Notes

Reaction equation

HRID 227716 reaction equation
[F:1][C:2]1[C:3]([N+:10]([O-:12])=[O:11])=[CH:4][C:5]([CH3:9])=[C:6]([CH:8]=1)[NH2:7].[N:13]([O-])=O.[Na+]>CC(O)=O.O>[F:1][C:2]1[CH:8]=[C:6]2[C:5]([CH:9]=[N:13][NH:7]2)=[CH:4][C:3]=1[N+:10]([O-:12])=[O:11]

Participants

5

Reactant 2

HCID 230701315-Fluoro-2-methyl-4-nitroanilineHCID 23668193Sodium Nitrite

Product 1

HCID 459336676-Fluoro-5-nitro-1H-indazoleYield 43%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

The product of Step (b) (1.22 g, 7.17 mmol, 1.0 equiv) was dissolved In AcOH (62 mL). NaNO2 (0.495 g, 7.17 mmol, 1.0 equiv) was dissolved in H2O (1.5 mL) and added all at once via pipet. The reaction was warmed to room temperature and stirred for 28 hours. The reaction mixture was concentrated en vacuo to provide an orange solid, which was dried azeotropically several times with hexanes. The residue was purified by flash chromatography (linear gradient 20→60% EtOAc/hexanes) to afford 550 mg (43%) of the title compound. MS (ES+) m/e 182 [M+H].

Workup

  1. additionadded all at once via pipet
  2. concentrationThe reaction mixture was concentrated en vacuo
  3. customto provide an orange solid, which
  4. dry with materialwas dried azeotropically several times with hexanes
  5. customThe residue was purified by flash chromatography (linear gradient 20→60% EtOAc/hexanes)

Sources & evidence

ORD record
ord-fcacd4e13c4f4b84899719c6035b0350
Source dataset
uspto-grants-2009_07
Patent number
US07560467B2

Reaction notes

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