Phthalimide → 8-Chloro-5-(1-ethylpropyl)-2,3-dihydro-1H-imidazo[1,2-a]benzimidazole
Reaction equation
Cl[C:2]1[N:6]([CH2:7][CH2:8]O)[C:5]2[C:10]([CH:15]([CH2:18][CH3:19])[CH2:16][CH3:17])=[CH:11][CH:12]=[C:13]([Cl:14])[C:4]=2[N:3]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CCOC(/[N:44]=N/C(OCC)=O)=O.C1(=O)NC(=O)C2=CC=CC=C12>O1CCCC1>[Cl:14][C:13]1[C:4]2[N:3]=[C:2]3[NH:44][CH2:8][CH2:7][N:6]3[C:5]=2[C:10]([CH:15]([CH2:18][CH3:19])[CH2:16][CH3:17])=[CH:11][CH:12]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 2-[2,4-Dichloro-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]ethanol (1.41 g, 4.681 mmol) in tetrahydrofuran (18 mL) were added triphenylphosphine (1.84 g, 7.022 mmol), diethylazodicarboxylate (ca. 2.2 mol/L in toluene, 3.19 mL, 7.022 mmol) and phthalimide (1.03 g, 7.022 mmol). The reaction mixture was stirred at room temperature for 2 hrs. The mixture was concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 0-30% ethyl acetate/n-hexane gradient mixture to give the mixture containing the title compound. To a solution of the crude material in tetrahydrofuran (12 mL) and ethanol (1 mL) was added hydrazine monohydrate (2 mL). The reaction mixture was stirred at room temperature for 7 hrs. The precipitate was removed by filtration. The filtrate was concentrated in vacuo, and the residue was recrystallized with ethyl acetate/tetrahydrofuran to give the title compound as a colorless solid (725.5 mg, 2.751 mmol, 59%).
Workup
- concentrationThe mixture was concentrated in vacuo
- customThe residue was purified by silica gel column chromatography
- washeluting with a 0-30% ethyl acetate/n-hexane gradient mixture
- customto give the mixture
Sources & evidence
- ORD record
- ord-cba97af73e934db68973a8dd2ed8232b
- Source dataset
- uspto-grants-2014_07
- Patent number
- US08785460B2
Reaction notes
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