Potassium Carbonate → 5,6-Dimethyl-1-(4-methyl-benzo[b]thiophen-3-ylmethyl)-1,3-dihydro-benzimidazol-2-one

HRID 1747305Notes

Reaction equation

HRID 1747305 reaction equation
[CH3:1][C:2]1[C:11]([CH3:12])=[CH:10][C:5]2[NH:6][C:7](=[O:9])[NH:8][C:4]=2[CH:3]=1.C([O-])([O-])=O.[K+].[K+].C[N+](C)(C)[CH2:21][C:22]1[C:23]2[C:30]([CH3:31])=[CH:29][CH:28]=[CH:27][C:24]=2[S:25][CH:26]=1.[I-].[H-].[Na+]>CC(N(C)C)=O.C(OCC)(=O)C.CO>[CH3:1][C:2]1[C:11]([CH3:12])=[CH:10][C:5]2[N:6]([CH2:21][C:22]3[C:23]4[C:30]([CH3:31])=[CH:29][CH:28]=[CH:27][C:24]=4[S:25][CH:26]=3)[C:7](=[O:9])[NH:8][C:4]=2[CH:3]=1

Participants

9

Reactant 5

HCID 11430Potassium CarbonateHCID 24758Sodium hydrideHCID 30165Iodide IonHCID 748535,6-Dimethyl-1H-benzo[d]imidazol-2(3H)-oneHCID 59497388Trimethyl-(4-methyl-benzo[b]thiophen-3-ylmethyl)-ammonium

Product 1

HCID 673605475,6-Dimethyl-1-(4-methyl-benzo[b]thiophen-3-ylmethyl)-1,3-dihydro-benzimidazol-2-one

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 8857Ethyl AcetateSolventHCID 31374DimethylacetamideSolvent

Conditions

Temperature
130 °C

Procedure

To a slurry of 5,6-Dimethyl-2-benzimidazolinone (0.2 g, 1.2 mmol) in DMA (2 mL) (poor solubility) were added K2CO3 (0.10 g, 0.74 mmol) and trimethyl-(4-methyl-benzo[b]thiophen-3-ylmethyl)-ammonium; iodide (0.21 g, 0.62 mmol). The heterogeneous reaction mixture was heated to 130° C. for 10 min. Since there was still un-reacted starting material left, NaH (15 mg, 0.38 mmol) was added to the reaction mixture and heated to 150° C. for 10 min. The reaction was complete. The reaction mixture was then diluted with ethyl acetate (some MeOH was added to solubilize the reaction mixture into the organic phase) and washed with water (×5). The organic phase was dried over Na2SO4 and concentrated. The resulting solid had poor solubility. To the solid, CH2Cl2 was added and the resulting solid was filtered. The filtered solid was identified as the desired product (with a minimal amount of excess 5,6-Dimethyl-2-benzimidazolinone). Therefore, this filtered solid was used for the next reaction. LCMS (ESMS): m/z 323.13 (M+H+).

Workup

  1. customSince there was still un-reacted
  2. waitleft
  3. temperatureheated to 150° C. for 10 min
  4. additionwas added
  5. washwashed with water (×5)
  6. dry with materialThe organic phase was dried over Na2SO4
  7. concentrationconcentrated
  8. additionTo the solid, CH2Cl2 was added
  9. filtrationthe resulting solid was filtered
  10. customTherefore, this filtered solid was used for the next reaction

Sources & evidence

ORD record
ord-9362ab5595f34e858ea47d497e6a1e52
Source dataset
uspto-grants-2015_10
Patent number
US09150556B2

Reaction notes

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