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

HRID 572683Notes

Reaction equation

HRID 572683 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 46.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 6-chloropyridazin-3-amine (16 g, 0.124 mol, Preparation #25) in methanol (200 mL) was added NaHCO3 (20.84 g, 0.24 mols). The reaction mixture was stirred for 30 min at RT and bromine (19.6 g, 0.124 mol, Spectrochem) added drop wise. Then reaction mixture was stirred for another 16 h and concentrated under vacuum. Crude material obtained was purified using silica gel column chromatography by eluting with 50% EtOAc in hexane to afford 4-bromo-6-chloropyridazin-3-amine 12 g (46%) as brown solid. 1H NMR (400 MHz, DMSO) δ 7.548 (s, 1H), 5.341 (br s, 2H); MS m/z=208.0 M+H+;

Workup

  1. customThen reaction mixture
  2. stirringwas stirred for another 16 h
  3. concentrationconcentrated under vacuum
  4. customCrude material obtained
  5. customwas purified
  6. washby eluting with 50% EtOAc in hexane

Sources & evidence

ORD record
ord-dabe8c0c08344f2d9a270274a50efc99
Source dataset
uspto-grants-2015_05
Patent number
US09029409B2

Reaction notes

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