Trifluoroacetic acid → 3-(4,5-Dibromo-3-chloro-thiophen-2-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine

HRID 1432715Notes

Reaction equation

HRID 1432715 reaction equation
[Br:1][C:2]1[S:6][C:5]([C:7]2[N:11]3[N:12]=[C:13]([CH3:21])[CH:14]=[C:15]([CH:16]([CH2:19][CH3:20])[CH2:17][CH3:18])[C:10]3=[N:9][C:8]=2[CH3:22])=[C:4]([Cl:23])[CH:3]=1.FC(F)(F)C(O)=O.C1C(=O)N([Br:38])C(=O)C1.[OH-].[Na+]>OS(O)(=O)=O>[Br:38][C:3]1[C:4]([Cl:23])=[C:5]([C:7]2[N:11]3[N:12]=[C:13]([CH3:21])[CH:14]=[C:15]([CH:16]([CH2:19][CH3:20])[CH2:17][CH3:18])[C:10]3=[N:9][C:8]=2[CH3:22])[S:6][C:2]=1[Br:1]

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 14798Sodium HydroxideHCID 67184N-bromobutanimideHCID 579329223-(5-Bromo-3-chloro-thiophen-2-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine

Product 1

HCID 579330503-(4,5-Dibromo-3-chloro-thiophen-2-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazineYield 94%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

To a solution of 3-(5-bromo-3-chloro-thiophen-2-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine (5.92 g, 14.34 mmol) and trifluoroacetic acid (40 mL) and 98% H2SO4 (10 ml) is added NBS (3.83 g, 21.15 mmol). After 10 minutes the solution is poured into ice, and made basic with 5M NaOH. The slurry is extracted with EtOAc (3×100 mL), the combined organic layers washed with water (2×400 mL), brine (400 mL), dried over MgSO4, filtered and concentrated to furnish the title compound (6.61 g, 13.44 mmol, 94%). 1H NMR (CDCl3) δ 0.87 (t, J=7.5 Hz, 6H), 1.72-1.92 (m, 4H), 2.47 (s, 3H), 2.52 (s, 3H), 3.25-3.34 (m, 1H), 6.72 (s, 1H). LC/MS (m/z): calcd. for C17H18Br2ClN3S (M+H)+: 489.9; found: 490.0.

Workup

  1. additionAfter 10 minutes the solution is poured into ice
  2. extractionThe slurry is extracted with EtOAc (3×100 mL)
  3. washthe combined organic layers washed with water (2×400 mL), brine (400 mL)
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-50136b62c9974bb5b1cdde7febe23637
Source dataset
uspto-grants-2009_11
Patent number
US07612067B2

Reaction notes

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