p-Toluenesulfonic acid → 8-Bromo-6-phenylimidazo[1,2-B]pyridazine

HRID 1755308Notes

Reaction equation

HRID 1755308 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[N:5]=[N:4][C:3]=1[NH2:14].Cl[CH2:16][CH:17](OCC)OCC.CC1C=CC(S(O)(=O)=O)=CC=1>C(O)(C)C>[Br:1][C:2]1[C:3]2[N:4]([CH:16]=[CH:17][N:14]=2)[N:5]=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:7]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 121282-Chloro-1,1-diethoxyethaneHCID 583863604-Bromo-6-phenylpyridazin-3-amine

Product 1

HCID 717440288-Bromo-6-phenylimidazo[1,2-B]pyridazineYield 46%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

A solution of 4-bromo-6-phenylpyridazin-3-amine (1.2 g, 4.8 mmol), 2-chloro-1,1-diethoxyethane (0.884 g, 5.74 mmol), PTSA (1.09 g, 5.74 mmol) in isopropanol (25 mL) was heated to 80° C. for 40 h. After cooling to room temperature, the solution was concentrated in vacuo. The resulting mixture was treated with a saturated aq. NaHCO3 solution (50 mL), extracted with dichloromethane (50 mL×3), dried over Na2SO4, filtered and concentrated. The residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1) to give 8-bromo-6-phenylimidazo[1,2-b]pyridazine (0.6 g, 46%) as a white solid. LC-MS: [M+H]+, 274.0, tR=1.541 min.

Workup

  1. concentrationthe solution was concentrated in vacuo
  2. additionThe resulting mixture was treated with a saturated aq. NaHCO3 solution (50 mL)
  3. extractionextracted with dichloromethane (50 mL×3)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1)

Sources & evidence

ORD record
ord-2d24757d24ab4fba9520bb900270d5b1
Source dataset
uspto-grants-2015_10
Patent number
US09169259B2

Reaction notes

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