4-Chlorobenzaldehyde → 1-(4-chlorophenyl)-2-(1-trityl-1H-imidazol-2-yl)ethanol

HRID 423098Notes

Reaction equation

HRID 423098 reaction equation
C([Li])CCC.[CH3:6][C:7]1[N:8]([C:12]([C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:9]=[CH:10][N:11]=1.[Cl:31][C:32]1[CH:39]=[CH:38][C:35]([CH:36]=[O:37])=[CH:34][CH:33]=1>C1COCC1>[Cl:31][C:32]1[CH:39]=[CH:38][C:35]([CH:36]([OH:37])[CH2:6][C:7]2[N:8]([C:12]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)([C:19]3[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=3)[C:25]3[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=3)[CH:9]=[CH:10][N:11]=2)=[CH:34][CH:33]=1

Participants

5

Reactant 3

HCID 77264-ChlorobenzaldehydeHCID 6182462-Methyl-1-tritylimidazole2×HCID 178418339Butyllithium

Product 1

HCID 577503131-(4-chlorophenyl)-2-(1-trityl-1H-imidazol-2-yl)ethanolYield 63.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

Butyllithium (1.6M in hexanes) (4.24 mL, 6.78 mmol) was added dropwise to 2-methyl-1-trityl-1H-imidazole (Intermediate 85) (2.0 g, 6.16 mmol) in THF (30 mL) cooled to −78° C. over a period of 20 minutes under nitrogen. The resulting dark red solution was stirred at −78° C. for 30 minutes then a solution of 4-Chlorobenzaldehyde (0.867 g, 6.16 mmol) in THF (10 mL) added dropwise. The reaction was allowed to warm slowly to 0° C. then quenched with saturated NH4Cl (50 mL) and extracted with TBME (2×). The combined extracts were washed with brine, dried over MgSO4, concentrated by evaporation then purified by flash silica chromatography, elution gradient 20 to 30% EtOAc in isohexane. Pure fractions were evaporated to dryness to afford 1-(4-chlorophenyl)-2-(1-trityl-1H-imidazol-2-yl)ethanol (1.810 g, 63.1%) as a colourless solid.

Workup

  1. temperatureto warm slowly to 0° C.
  2. customthen quenched with saturated NH4Cl (50 mL)
  3. extractionextracted with TBME (2×)
  4. washThe combined extracts were washed with brine
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated by evaporation
  7. customthen purified by flash silica chromatography, elution gradient 20 to 30% EtOAc in isohexane
  8. customPure fractions were evaporated to dryness

Sources & evidence

ORD record
ord-289fb758c3e54991984c11f673c21a31
Source dataset
uspto-grants-2012_01
Patent number
US08101623B2

Reaction notes

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