Urea → 3-Cyclohexyl-5-ethoxy-1,3-dihydro-2H-benzimidazol-2-one

HRID 1081463Notes

Reaction equation

HRID 1081463 reaction equation
[CH2:1]([O:3][C:4]1[CH:9]=[CH:8][C:7]([NH2:10])=[C:6]([NH:11][CH:12]2[CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]2)[CH:5]=1)[CH3:2].N[C:19](N)=[O:20].CCOC(C)=O>CC1C=CC(C)=C(C)C=1C>[CH:12]1([N:11]2[C:6]3[CH:5]=[C:4]([O:3][CH2:1][CH3:2])[CH:9]=[CH:8][C:7]=3[NH:10][C:19]2=[O:20])[CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]1

Participants

5

Reactant 3

HCID 1176UreaHCID 8857Ethyl AcetateHCID 229225154-Ethoxy-1-amino-2-cyclohexylaminobenzene

Product 1

HCID 152315443-Cyclohexyl-5-ethoxy-1,3-dihydro-2H-benzimidazol-2-oneYield 39.3%

Reagents, catalysts & solvents 1

HCID 102631,2,3,4-TetramethylbenzeneSolvent

Procedure

A mixture of 3.05 g of the oil obtained in step B) and 1.6 g of urea in 8 ml of 1,2,3,4-tetramethylbenzene is heated at 170°-180° C. for 1 hour 30 minutes. After cooling, it is taken up with AcOEt, washed with water and dried over sodium sulfate and the solvent is evaporated off under vacuum. The residue is taken up with hexane and the brown precipitate formed is filtered off. The precipitate is chromatographed on silica using a DCM/AcOEt mixture (50/50; v/v) as the eluent to give 1.33 g of the expected product, which was precipitated with isopropyl ether. M.p.=203° C.

Workup

  1. temperatureis heated at 170°-180° C. for 1 hour 30 minutes
  2. temperatureAfter cooling
  3. washwashed with water
  4. dry with materialdried over sodium sulfate
  5. customthe solvent is evaporated off under vacuum
  6. customthe brown precipitate formed
  7. filtrationis filtered off
  8. customThe precipitate is chromatographed on silica using a DCM/AcOEt mixture (50/50; v/v) as the eluent

Sources & evidence

ORD record
ord-31f58be9b0f541ac87ac226a98d031d2
Source dataset
uspto-grants-1996_12
Patent number
US05585394

Reaction notes

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