Hydrochloric Acid → Palladium

Participants

Reaction Conditions

Reaction Steps

The reaction of Example 1 (reaction scale: 10 mmol of bromophenyl pyrazole) was conducted with 0.1 mole % of Pd2(dba)3. After the reaction was judged to be essentially complete, the reaction mixture was neutralized with 1N aqueous HCl to a pH of 7.0 to 7.5. The crude product, whose palladium level was 270 ppm, was dissolved in acetone (16 mL/g of bromophenyl pyrazole starting material) and THF (2.65 mL/g) at 50° C. TMT (0.23 equiv.) was added, and the mixture was stirred at 50° C. for 15 min, cooled to room temperature, and filtered three times through a Darco zeta pad. A sample of filtrate was evaporated to dryness, affording a solid containing 92 ppm of palladium. The remaining filtrate was concentrated and recrystallized by adding water, affording 2′-(5-ethyl-3,4-diphenyl-1H-pyrazol-1-yl)-[1,1′]-biphenyl-3-ol containing 51 ppm of palladium.

Provenance & Evidence