Water → Ethyl 1-tritylpyrazole-4-carboxylate

HRID 1458579Notes

Reaction equation

HRID 1458579 reaction equation
[NH:1]1[CH:5]=[C:4]([C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH:3]=[N:2]1.[H-].[Na+].[C:13](Cl)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.O>O1CCCC1>[C:14]1([C:13]([C:20]2[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=2)([C:26]2[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=2)[N:1]2[CH:5]=[C:4]([C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH:3]=[N:2]2)[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1

Participants

6

Reactant 4

HCID 962WaterHCID 6456Trityl chloride2×HCID 24758Sodium hydride2×HCID 142179ethyl 1H-pyrazole-4-carboxylate

Product 1

HCID 10523968Ethyl 1-tritylpyrazole-4-carboxylateYield 56%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

Ethyl 1 H-pyrazole-4-carboxylate (1.50 g, 10.7 mmol) was added in portions to a stirred suspension of sodium hydride (353 mg, 80% oil dispersion, 11.8 mmol) in anhydrous tetrahydrofuran (100 ml) under nitrogen at room temperature. After 20 minutes, the mixture was cooled to 0° C. and trityl chloride (3.28 g, 11.8 mmol) was added. The mixture was stirred at 0° C. for 4 h and allowed to warm to room temperature overnight. The mixture was then heated at 50° C. for 3 h, cooled, and further portions of sodium hydride (321 mg, 10.7 mmol) and trityl chloride (1.0 g, 3.59 mmol) were added. The mixture was heated at 50° C. for 2 h, cooled, treated with water (50 ml) and concentrated under reduced pressure. The product was extracted into ethyl acetate (200 ml), the solution was dried (MgSO4) and concentrated under reduced pressure. The residue was purified by flash chromatography (gradient elution with hexane/ethyl acetate) to give ethyl 1 -(triphenylmethyl)-pyrazole-4-carboxylate (2.273 g, 56%), as a white solid.

Workup

  1. temperatureto warm to room temperature overnight
  2. temperatureThe mixture was then heated at 50° C. for 3 h
  3. temperaturecooled
  4. temperatureThe mixture was heated at 50° C. for 2 h
  5. temperaturecooled
  6. concentrationconcentrated under reduced pressure
  7. extractionThe product was extracted into ethyl acetate (200 ml)
  8. dry with materialthe solution was dried (MgSO4)
  9. concentrationconcentrated under reduced pressure
  10. customThe residue was purified by flash chromatography (gradient elution with hexane/ethyl acetate)

Sources & evidence

ORD record
ord-d7499d99b29e448fa730ce8a7b01b39b
Source dataset
uspto-grants-1998_12
Patent number
US05852016

Reaction notes

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