1-((1,1-Dimethylethyl)dimethylsilyl)-1H-imidazole → Methyl 3-[(dipropylamino)carbonyl]-5-(1H-imidazol-2-yl)benzoate

HRID 14062Notes

Reaction equation

HRID 14062 reaction equation
[Si]([N:8]1[CH:12]=[CH:11][N:10]=[CH:9]1)(C(C)(C)C)(C)C.C([Li])CCC.[CH2:18]([N:21]([CH2:35][CH2:36][CH3:37])[C:22]([C:24]1[CH:25]=[C:26]([CH:31]=[C:32](I)[CH:33]=1)[C:27]([O:29][CH3:30])=[O:28])=[O:23])[CH2:19][CH3:20]>O1CCCC1.C(OCC)(=O)C.[Cl-].[Zn+2].[Cl-]>[CH2:35]([N:21]([CH2:18][CH2:19][CH3:20])[C:22]([C:24]1[CH:25]=[C:26]([CH:31]=[C:32]([C:9]2[NH:8][CH:12]=[CH:11][N:10]=2)[CH:33]=1)[C:27]([O:29][CH3:30])=[O:28])=[O:23])[CH2:36][CH3:37]

Participants

7

Reactant 3

HCID 1713851-((1,1-Dimethylethyl)dimethylsilyl)-1H-imidazoleHCID 21086179Methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoateHCID 178418339Butyllithium

Product 1

HCID 21086171Methyl 3-[(dipropylamino)carbonyl]-5-(1H-imidazol-2-yl)benzoate

Reagents, catalysts & solvents 3

HCID 3007855ZincchlorideCatalystHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a −70° C. stirred solution of 1-tert-butyldimethylsilylimidazole (602 mg, 3.3 mmol) in tetrahydrofuran (10 mL) is added n-butyllithium (1.6 M in hexanes, 2.3 mL, 3.63 mmol). After 30 min, zinc chloride (1 M in diethyl ether, 9.9 mL, 9.9 mmol) is added and the reaction mixture is warmed to 0° C. for 1 h. To this mixture is then added methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoate prepared by the method in Example SP-281, step 2 (1.17 g, 3 mmol) followed by palladium(0)tetrakis(triphenylphosphine) (173 mg, 0.15 mmol). The reaction mixture is heated at reflux for 15 h. The reaction mixture is diluted with ethyl acetate (50 mL), washed with water, and brine, dried (sodium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica gel, 1-5% methanol/methylene chloride) provides the title compound in pure form. 1H NMR (300 MHz, CDCl3) δ 8.64 (s, 1H), 8.14 (s, 1H), 7.97 (s, 1H), 7.19 (s, 2H), 3.96 (s, 3H), 3.51 (m, 2H), 3.32 (m, 2H), 1.73 (m, 2H), 1.57 (m, 2H), 1.01 (m, 3H), 0.73 (m, 3H).

Workup

  1. temperatureThe reaction mixture is heated
  2. temperatureat reflux for 15 h
  3. washwashed with water, and brine
  4. dry with materialdried (sodium sulfate)
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customPurification by flash column chromatography (silica gel, 1-5% methanol/methylene chloride)

Sources & evidence

ORD record
ord-b6666355a0f3409d9b305dcb26d75071
Source dataset
uspto-grants-2010_06
Patent number
US07727997B2

Reaction notes

Loading…