Binap, (A+-)- → 1-(2,4-Dimethoxyphenyl)-4-(2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-yl)piperazine

Participants

Reaction Steps

To the toluene (10 mL) mixture solution of 5-bromo-2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran (400 mg, 1.49 mmol) synthesized in Reference example 4, 1-(2,4-dimethoxyphenyl)piperazine (495 mg, 2.23 mmol), palladium acetate (17 mg, 0.0745 mmol) and BINAP (139 mg, 0.224 mmol), sodium t-butoxide (286 mg, 2.98 mmol) was added and stirred for 15 hours under reflux. After cooling to room temperature, water was added to the reaction solution, and extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure. The residue was purified by silica gel chromatography (hexane-ethyl acetate 95:5-85:15) and crystallized from ethyl acetate-hexane to obtain the title compound 340 mg (yield 56%). Melting point was 154 to 156° C.

Provenance & Evidence