Citric Acid → 5-tert-butyl-1-(2'-chloro-1,1'-biphenyl-3-yl)-1H-pyrazole-3-carboxylic acid

Participants

Reaction Steps

To a solution of ethyl 1-(3-bromophenyl)-5-tert-butyl-1H-pyrazole-3-carboxylate and 2-chlorophenylboronic acid (0.279 g, 1.78 mmol) in n-propanol:water (2.35 ml:0.482 ml) mixture were added palladium acetate (0.005 g), triphenylphosphine (0.016 g) and 2N sodium carbonate (0.497 ml) and the solution was refluxed for 16 hours. To the reaction, a 2N solution of NaOH (1.5 ml) was added and refluxed for an additional 2 hours. The solution was cooled, acidified with 10% citric acid and extracted into ethyl acetate. The organic phase was washed with brine, dried over sodium sulfate, filtered and concentrated to give 0.212 g of 5-tert-butyl-1-(2′-chloro-1,1′-biphenyl-3-yl)-1H-pyrazole-3-carboxylic acid.

Provenance & Evidence