Pyridine → 5-tert-Butyl-2-p-tolyl-2H-pyrazole-3-carboxylic acid ethyl ester

Participants

Reaction Steps

To a round bottom flask containing 5-tert-Butyl-2H-pyrazole-3-carboxylic acid ethyl ester (0.5 g, 2.6 mmol) stirring in 25 mL DCM was added Pyridine (0.95 mL, 11.7 mmol), p-tolylboronic acid (1.1 g, 8.1 mmol), Cu(OAc)2 (0.75 g, 4.1 mmol) and 4 A molecular sieves (0.75 g). The reaction stirred at room temperature for 14 h under air. The resulting mixture was filtered through a pad of diatomaceous earth and the filtrate concentrated in vacuo to afford a light green solid. The crude material was purified by Flash chromatography to afford (0.64 g, 83%) the desired product as a clear oil (0-50% EtOAc:hexanes on silica gel). Expected mass=286. Observed mass=287.

Provenance & Evidence