Potassium Carbonate → 3-[3-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-hexanoic acid ethyl ester

HRID 1747287Notes

Reaction equation

HRID 1747287 reaction equation
[CH3:1][C:2]1[C:10]2[C:9]([CH2:11][N:12]3[C:16]4[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=4[NH:14][C:13]3=[O:21])=[CH:8][S:7][C:6]=2[CH:5]=[CH:4][CH:3]=1.[OH-].C([N+](C)(C)C)[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1.C([O-])([O-])=[O:35].[K+].[K+].[CH3:40][C:41](N(C)C)=[O:42]>CO.C(OCC)(=O)C>[CH2:41]([O:42][C:24](=[O:35])[CH2:29][CH:28]([N:14]1[C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][C:16]=2[N:12]([CH2:11][C:9]2[C:10]3[C:2]([CH3:1])=[CH:3][CH:4]=[CH:5][C:6]=3[S:7][CH:8]=2)[C:13]1=[O:21])[CH2:27][CH2:26][CH3:25])[CH3:40]

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 31374DimethylacetamideHCID 66854Benzyltrimethylammonium hydroxide2×HCID 594973791-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-1,3-dihydro-benzimidazol-2-one

Product 1

HCID 594976173-[3-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-hexanoic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 887MethanolSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of 1-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-1,3-dihydro-benzimidazol-2-one (0.2 g, 0.68 mmol) in DMA (5 mL) were added ethyl trans-2-hexanoate (0.19 g, 1.4 mmol) and benzyltrimethyl ammonium hydroxide in MeOH (0.43 g, 1.0 mmol) (Benzyltrimethyl ammonium hydroxide in MeOH can be replaced with K2CO3 (2eq) as a base). The reaction mixture was heated to 60° C. for 20 h. The reaction mixture was diluted with ethyl acetate and washed with water (×4). The organic phase was dried over Na2SO4 and concentrated. The resulting residue was attempted to dissolve in a mixture of CH2Cl2 and MeOH to load to a prep TLC. However, some insoluble material was present. This insoluble solid was filtered, however, the structure of the filtered solid couldn't be characterized (no aliphatic region in NMR). The filtrate was concentrated and resulting residue was purified by silica gel prep TLC using 98:2 CH2Cl2:MeOH as an eluent to afford 0.2 g of the desired product (with methyl ester instead of ethyl ester) as an oil. LCMS (ESMS): m/z 423.46 (M+H+).

Workup

  1. washwashed with water (×4)
  2. dry with materialThe organic phase was dried over Na2SO4
  3. concentrationconcentrated
  4. dissolutionto dissolve in a mixture of CH2Cl2 and MeOH
  5. filtrationThis insoluble solid was filtered
  6. concentrationThe filtrate was concentrated
  7. customresulting residue
  8. customwas purified by silica gel prep TLC

Sources & evidence

ORD record
ord-e8f2ba3c92e04ed582309e59a17e1dfb
Source dataset
uspto-grants-2015_10
Patent number
US09150556B2

Reaction notes

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