Thionyl bromide → Methyl 5-bromo-4-(imidazo[1,2-b]pyridazin-3-yl)thiophene-2-carboxylate

HRID 2046406Notes

Reaction equation

HRID 2046406 reaction equation
[N:1]1[CH:2]=[C:3]([C:10]2[CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[S:13][CH:14]=2)[N:4]2[C:9]=1[CH:8]=[CH:7][CH:6]=[N:5]2.S(Br)([Br:21])=O>>[Br:21][C:14]1[S:13][C:12]([C:15]([O:17][CH3:18])=[O:16])=[CH:11][C:10]=1[C:3]1[N:4]2[N:5]=[CH:6][CH:7]=[CH:8][C:9]2=[N:1][CH:2]=1

Participants

3

Reactant 2

HCID 68176Thionyl bromideHCID 58046452Methyl 4-(imidazo[1,2-b]pyridazin-3-yl)thiophene-2-carboxylate

Product 1

HCID 58046405Methyl 5-bromo-4-(imidazo[1,2-b]pyridazin-3-yl)thiophene-2-carboxylate

Conditions

Temperature
50 °C

Procedure

Methyl 4-(imidazo[1,2-b]pyridazin-3-yl)thiophene-2-carboxylate (690 mg, 2.66 mmol) was dissolved in thionyl bromide (5 mL, 64.5 mmol) and heated at 50° C. in a sealed tube for 4 h. The solution poured over ice and quenched with ammonium hydroxide. The aqueous layer was extracted with dichloromethane (×3). The organic layers put together, dried with magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography to afford the title compound as a light brown solid. 1H NMR (500 MHz, CD3SOCD3) δ 8.66 (d, 1H); 8.27 (s, 1H); 8.25 (s, 1H); 8.25 (d, 1H); 7.35 (dd, 1H); 3.85 (s, 3H). LRMS (APCI) calc'd for (C12H8BrN3O2S) [M+H]+, 338.0. found 337.9.

Workup

  1. additionThe solution poured over ice
  2. customquenched with ammonium hydroxide
  3. extractionThe aqueous layer was extracted with dichloromethane (×3)
  4. dry with materialdried with magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by flash chromatography

Sources & evidence

ORD record
ord-cfb5bdcebc09410dad77739f53b490a1
Source dataset
uspto-grants-2013_11
Patent number
US08592425B2

Reaction notes

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