Azobisisobutyronitrile → Ethyl 4-[4-chloro-7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]butanoate

HRID 1398758Notes

Reaction equation

HRID 1398758 reaction equation
[CH2:1]([CH:3]([C:6]1[C:11]2[N:12]([CH2:16][CH2:17][CH2:18][C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:13](=[O:15])[NH:14][C:10]=2[CH:9]=[CH:8][CH:7]=1)[CH2:4][CH3:5])[CH3:2].N(C(C)(C)C#N)=NC(C)(C)C#N.[Cl:36]N1C(=O)CCC1=O>ClC1C=CC=CC=1>[Cl:36][C:9]1[C:10]2[NH:14][C:13](=[O:15])[N:12]([CH2:16][CH2:17][CH2:18][C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:11]=2[C:6]([CH:3]([CH2:4][CH3:5])[CH2:1][CH3:2])=[CH:7][CH:8]=1

Participants

5

Conditions

Temperature
85 °C

Procedure

To a solution of ethyl 4-[7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]butanoate (9.7 g, 30.5 mmol) and 2,2′-azobisisobutyronitrile (AIBN; 0.5 g, 3.05 mmol) in chlorobenzene (100 mL) was added N-chlorosuccinimide (NCS; 4.35 g, 32.6 mmol) in portions at 65° C., and the mixture was stirred at 80-90° C. for 2 days. After cooled to room temperature, the reaction mixture was partitioned between ethyl acetate (50 mL) and water (50 mL). The aqueous phase was extracted with ethyl acetate (100 ml×3), washed with brine (100 mL), dried over anhydrous sodium sulfate and purified by silica gel column (petroleum ether/ethyl acetate, 50/1) to afford the title compound (6.8 g, 61%) as yellow oil.

Workup

  1. temperatureAfter cooled to room temperature
  2. customthe reaction mixture was partitioned between ethyl acetate (50 mL) and water (50 mL)
  3. extractionThe aqueous phase was extracted with ethyl acetate (100 ml×3)
  4. washwashed with brine (100 mL)
  5. dry with materialdried over anhydrous sodium sulfate
  6. custompurified by silica gel column (petroleum ether/ethyl acetate, 50/1)

Sources & evidence

ORD record
ord-68193b27fb76400bb780747f2d739c08
Source dataset
uspto-grants-2014_12
Patent number
US08901141B2

Reaction notes

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