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

HRID 594047Notes

Reaction equation

HRID 594047 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 50%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 6-chloropyridazin-3-amine (1.0 equiv) in MeOH (1M) at room temperature was added sodium bicarbonate (2.0 equiv.) and the resulting suspension was stirred at room temperature for 30 min before the dropwise addition of bromine (1.0 equiv.). The reaction mixture was stirred for 20 h. Upon concentration under vacuo, the crude residue was purified via silica gel column chromatography eluting with 100% heptanes to 80% ethyl acetate:heptanes to yield 4-bromo-6-chloropyridazin-3-amine in 50% yield. LCMS (m/z) (M+H)=207.8/209.8, Rt=0.47 min. 1H NMR (400 MHz, <cdcl3>) δ ppm 5.31-5.63 (m, 2H) 7.46-7.61 (m, 1H).

Workup

  1. concentrationUpon concentration under vacuo
  2. customthe crude residue was purified via silica gel column chromatography
  3. washeluting with 100% heptanes to 80% ethyl acetate

Sources & evidence

ORD record
ord-a6266e6de88242e48d69ca3ea1c0fac4
Source dataset
uspto-grants-2016_01
Patent number
US09242969B2

Reaction notes

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