Water → Ethyl 1-tritylpyrazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence