Potassium Carbonate → tert-Butyl 4-(4-(4-(benzyloxy)-4'-(trifluoromethyl)biphenyl-3-yl)pyridin-2-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 4-(4-(2-(benzyloxy)-5-chlorophenyl)pyridin-2-yl)piperazine-1-carboxylate (Preparation 116, 1.10 g, 2.29 mmol), 4-(trifluoromethyl)phenylboronic acid (866 mg, 4.58 mmol), di-μ-chlorobis[5-chloro-2-[(4-chlorophenyl)(hydroxyimino)methyl]phenyl]palladium (II) dimer (93 mg, 0.114 mmol), tri-tert-butylphosphonium tetrafluoroborate (66 mg, 0.228 mmol), potassium carbonate (635 mg, 4.60 mmol) and tetrabutyl ammonium hydroxide (1M in methanol, 0.46 mL, 0.46 mmol) were combined in a microwave vial. Dimethylformamide (12 mL) was added and the vial was sealed. The mixture was heated at 130° C. for 2 hours in a microwave and then partitioned between ethyl acetate (15 mL) and water (5 mL). The organic layer was separated, washed with brine (5 mL), dried over anhydrous MgSO4, filtered and concentrated in vacuo. The residue was dissolved in dimethylformamide (12 mL) and 4-(trifluoromethyl)phenylboronic acid (866 mg, 4.58 mmol), di-mu-chlorobis[5-chloro-2-[(4-chlorophenyl)(hydroxyimino)methyl]phenyl]palladium (II) dimer (93 mg, 0.114 mmol), tri-tert-butylphosphonium tetrafluoroborate (66 mg, 0.228 mmol), potassium carbonate (635 mg, 4.60 mmol) and tetrabutyl ammonium hydroxyde (1M in methanol, 0.46 mL, 0.46 mmol) were added. The mixture was heated at 130° C. for 1 hour in microwave and then partitioned between ethyl acetate and water. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The oil residue was purified on silica gel by Biotage (5% to 80% ethyl acetate in heptane over 20 CV) to give the title compound as a white solid (655 mg, 48%).

Provenance & Evidence