Sodium Hydroxide → 3-(4,5-Dibromo-3-methyl-thiophen-2-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine

HRID 1432611Notes

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]([CH3:23])[CH:3]=1.[Br:24]Br.[OH-].[Na+]>CC(O)=O>[Br:24][C:3]1[C:4]([CH3:23])=[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

Conditions

Temperature: 110 °C

Procedure

To a solution of 3-(5-bromo-3-methyl-thiophen-2-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine (4.00 g, 10.20 mmol) and AcOH (40 mL) is added Br2 (0.57 mL, 11.21 mmol) and the solution heated at 110° C. overnight. Br2 (0.57 mL, 11.21 mmol) is added and the solution heated at 110° C. for 2 hours. The solution is poured into 5 M NaOH (200 mL) and ice (200 mL). The slurry is extracted with EtOAc (2×150 mL). The combined organic layers are washed with water (200 mL), 20% NaHSO3 (200 mL), sat. NaHCO3 (200 mL) dried over MgSO4, filtered and concentrated. The residue is purified by ISCO (5%-15% EtOAc gradient) furnish the title compound (2.66 g, 5.64 mmol, 55%). 1H NMR (CDCl3) δ 0.86 (t, J=7.5 Hz, 6H), 1.72-1.91 (m, 4H), 2.12 (s, 3H), 2.43 (s, 3H), 2.50 (s, 3H), 3.25-3.35 (m, 1H), 6.69 (s, 1H). LC/MS (m/z): calcd. for C18H21Br2N3S (M+H)+: 470.0; found: 470.3.

Workup

temperaturethe solution heated at 110° C. for 2 hours
extractionThe slurry is extracted with EtOAc (2×150 mL)
washThe combined organic layers are washed with water (200 mL), 20% NaHSO3 (200 mL), sat. NaHCO3 (200 mL)
dry with materialdried over MgSO4
filtrationfiltered
concentrationconcentrated
customThe residue is purified by ISCO (5%-15% EtOAc gradient)

Sources & evidence

ORD record: ord-8237637569f2493c9d9f5857e1508ae7
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07612067B2

Reaction notes

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