2-Thiophenecarboxaldehyde → 5-(Benzoxazol-2-yl)-2-(thiophen-2-yl)-1-(tetrahydropyran-4-yl)benzimidazole

HRID 74212Notes

Reaction equation

HRID 74212 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[C:2]1[C:10]1[CH:11]=[CH:12][C:13]([NH:17][CH:18]2[CH2:23][CH2:22][O:21][CH2:20][CH2:19]2)=[C:14]([CH:16]=1)[NH2:15].[S:24]1[CH:28]=[CH:27][CH:26]=[C:25]1[CH:29]=O.OOS([O-])=O.[K+].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C.O>[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[C:2]1[C:10]1[CH:11]=[CH:12][C:13]2[N:17]([CH:18]3[CH2:23][CH2:22][O:21][CH2:20][CH2:19]3)[C:29]([C:25]3[S:24][CH:28]=[CH:27][CH:26]=3)=[N:15][C:14]=2[CH:16]=1

Participants

7

Reactant 4

HCID 73642-ThiophenecarboxaldehydeHCID 11430Potassium CarbonateHCID 23707502Potassium hydroxy sulfiteHCID 674988065-(Benzoxazol-2-yl)-2-(tetrahydropyran-4-yl)aminoaniline

Product 1

HCID 674982805-(Benzoxazol-2-yl)-2-(thiophen-2-yl)-1-(tetrahydropyran-4-yl)benzimidazoleYield 36%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

5-(Benzoxazol-2-yl)-2-(tetrahydropyran-4-yl)aminoaniline (see Working Example 20-2) (0.13 g, 0.42 mmol) was dissolved in DMF (3 mL) and water (0.1 mL), 2-thiophenecarbaldehyde (0.05 g, 0.45 mmol) was added followed by oxone (0.17 g, 0.28 mmol), and this was stirred at room temperature for 2.5 hours. Aqueous potassium carbonate solution (0.10 g/15 mL) was added to the reaction solution. This was extracted with ethyl acetate, washed with water, and after drying over magnesium sulfate, this was concentrated and purified by silica gel column chromatography. The crystals obtained were washed with hexane and a small amount of ethyl acetate, and dried to yield the title compound (60 mg, 36% yield) as light brown crystals.

Workup

  1. extractionThis was extracted with ethyl acetate
  2. washwashed with water
  3. dry with materialafter drying over magnesium sulfate
  4. concentrationthis was concentrated
  5. custompurified by silica gel column chromatography
  6. customThe crystals obtained
  7. washwere washed with hexane
  8. dry with materiala small amount of ethyl acetate, and dried

Sources & evidence

ORD record
ord-a987402ca7234d9289113b220d456175
Source dataset
uspto-grants-2014_09
Patent number
US08829035B2

Reaction notes

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