Sodium Nitrite → 5-Bromo-7-iodo-1H-indazole

HRID 1678256Notes

Reaction equation

HRID 1678256 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([CH3:8])[C:5]([NH2:9])=[C:4]([I:10])[CH:3]=1.[N:11]([O-])=O.[Na+]>C(O)(=O)C.O>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[C:4]([I:10])[CH:3]=1)[NH:9][N:11]=[CH:8]2

Participants

5

Reactant 2

HCID 23668193Sodium NitriteHCID 581501564-Bromo-2-iodo-6-methylaniline

Product 1

HCID 590242185-Bromo-7-iodo-1H-indazoleYield 95.1%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

4-bromo-2-iodo-6-methyl-phenylamine (31.08 g, 99.6 mmol) was dissolved in glacial acetic acid (400 mL) in a 1 L round bottom flask equipped with a stir bar. The flask was then charged in one portion with sodium nitrite (7.56 g, 109.6 mmol) dissolved in water (18.7 mL). The mixture was stirred for about 15 minutes then the solvents were removed by evaporation on a rotovap at a bath temperature of about 35° C. The residue was stirred with water (200 mL) for 15 minutes and the resulting solid was collected by filtration and dried to yield 5-bromo-7-iodo-1H-indazole (30.6 g, 95%) as a brownish-tan solid; (DMSO-d6, 400 MHz) δ 13.6 (bs, 1H), 8.24 (s, 1H), 8.04 (d, J=1.54 Hz, 1H), and 7.88 (d, J=1.54 Hz, 1H); RP-HPLC (Table 1, Method e) Rt=3.63 min; m/z: (M−H)− 322.8.

Workup

  1. customequipped with a stir bar
  2. customthe solvents were removed by evaporation on a rotovap at a bath temperature of about 35° C
  3. stirringThe residue was stirred with water (200 mL) for 15 minutes
  4. filtrationthe resulting solid was collected by filtration
  5. customdried

Sources & evidence

ORD record
ord-d5917f193637426c8334612f66c94c5d
Source dataset
uspto-grants-2011_08
Patent number
US08008481B2

Reaction notes

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