6-Amino-3-chloropyridazine → 3-Amino-4-bromo-6-chloropyridazine

HRID 1755281Notes

Reaction equation

HRID 1755281 reaction equation
[Cl:1][C:2]1[N:7]=[N:6][C:5]([NH2:8])=[CH:4][CH:3]=1.C([O-])(O)=O.[Na+].[Br:14]Br>CO>[Br:14][C:4]1[CH:3]=[C:2]([Cl:1])[N:7]=[N:6][C:5]=1[NH2:8]

Participants

5

Reactant 3

HCID 216436-Amino-3-chloropyridazineHCID 24408BromineHCID 516892Sodium Bicarbonate

Product 1

HCID 220244193-Amino-4-bromo-6-chloropyridazineYield 65.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a suspension of 6-chloropyridazin-3-amine (30 g, 232 mmol), NaHCO3 (39 g, 464 mmol) and methanol (576 mL) was added Br2 (11.9 mL, 232 mmol) drop wise over 30 minutes at room temperature. The mixture was stirred for 16 h then filtered and concentrated in vacuo. The residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1) to give 4-bromo-6-chloropyridazin-3-amine (31.5 g, 65%) as a light orange solid. LC-MS: [M+H]+, 207.9, 209.9, tR=1.189 min.

Workup

  1. filtrationthen filtered
  2. concentrationconcentrated in vacuo
  3. customThe residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1)

Sources & evidence

ORD record
ord-5f453c07951b4eebb4fc1e912b508130
Source dataset
uspto-grants-2015_10
Patent number
US09169259B2

Reaction notes

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