Bromine → 4-Bromo-6-chloro-5-phenylpyridazin-3-amine

HRID 2239839Notes

Reaction equation

HRID 2239839 reaction equation
[Cl:1][C:2]1[N:7]=[N:6][C:5]([NH2:8])=[CH:4][C:3]=1[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.C([O-])(O)=O.[Na+].[Br:20]Br>CO>[Br:20][C:4]1[C:3]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)=[C:2]([Cl:1])[N:7]=[N:6][C:5]=1[NH2:8]

Participants

5

Reactant 3

HCID 24408BromineHCID 516892Sodium BicarbonateHCID 569536546-Chloro-5-phenylpyridazin-3-amine

Product 1

HCID 866117234-Bromo-6-chloro-5-phenylpyridazin-3-amineYield 91.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a suspension of 6-chloro-5-phenylpyridazin-3-amine (1.01 g, 4.9 mmol) from 1a in methanol (25 mL) under nitrogen was added NaHCO3 (1.09 g, 13.0 mmol). At 0° C., bromine (0.55 M in methanol, 10 mL, 5.5 mmol) was added over 5 min. After 1 h, the cold bath was removed, and the reaction mixture was stirred at room temperature for 6 h. After concentrating in vacuo, the residue was taken up in CH2Cl2 and saturated aqueous Na2S2O5, and the layers were separated. The organic layer was washed with saturated aqueous NaHCO3 and brine, dried over Na2SO4, filtered, and concentrated in vacuo to give crude 4-bromo-6-chloro-5-phenylpyridazin-3-amine (1.28 g).

Workup

  1. customthe cold bath was removed
  2. concentrationAfter concentrating in vacuo
  3. customsaturated aqueous Na2S2O5, and the layers were separated
  4. washThe organic layer was washed with saturated aqueous NaHCO3 and brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-8b13b96cfd0f4107a88d095801822b9b
Source dataset
uspto-grants-2010_05
Patent number
US07723336B2

Reaction notes

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