1-Bromo-3-chloropropane → 1-(3-chloropropyl)-3-methyl-1H-benzo[d]imidazol-2(3H)-one
Reaction equation
[CH3:1][N:2]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[NH:4][C:3]1=[O:11].Br[CH2:13][CH2:14][CH2:15][Cl:16].C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O.C(OCC)(=O)C>[Cl:16][CH2:15][CH2:14][CH2:13][N:4]1[C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[N:2]([CH3:1])[C:3]1=[O:11]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 65 °C
Procedure
A mixture of 1-methyl-1H-benzo[d]imidazol-2(3H)-one (2 g, 13.5 mmol, 1 equiv), 1-bromo-3-chloropropane (3.98 ml, 40.5 mmol, 3 equiv), and potassium carbonate (2.79 g, 20.25 mmol, 1.5 equiv) in N,N-dimethylformamide was heated at 65° C. for 16 h. The reaction was cooled to ambient temperature and diluted with ethyl acetate. After being washed with water and brine, the organic layer was dried over MgSO4, filtered, and concentrated in vacuo. The resulting residue was purified using the Biotage chromatography system (SNAP 100 g cartridge, Rf=0.6, gradient—10%-50% ethyl acetate/hexanes) to afford 1-(3-chloropropyl)-3-methyl-1H-benzo[d]imidazol-2(3H)-one as a clear oil (2.57 g, 85%); 1H NMR (400 MHz, DMSO-d6): δ 2.05-2.12 (m, 1H); 2.14-2.21 (m, 1H); 3.32 (s, 3H); 3.53 (t, 1H, J=6.8 and 6.4 Hz); 3.66 (t, 1H, J=6.4 Hz); 3.92-3.97 (m, 2H); 7.05-7.09 (m, 2H); 7.12-7.16 (m, 1H); 7.17-7.21 (m, 1H); MS for C11H13ClN2O m/z 226.07 (M+H)+.
Workup
- temperatureThe reaction was cooled to ambient temperature
- washAfter being washed with water and brine
- dry with materialthe organic layer was dried over MgSO4
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe resulting residue was purified
Sources & evidence
- ORD record
- ord-e7d9e18eb4b247e4a7a02fd6e5a46ad1
- Source dataset
- uspto-grants-2014_04
- Patent number
- US08691836B2
Reaction notes
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