Phosphinic Acid → 2-tert-Butyl-6-((2-methoxybiphenyl-3-yl)(phenyl)methyl)phenol

Participants

Reaction Steps

A solution of 15 (1.02 g, 1.93 mmol) in acetonitrile (24 mL) was treated with 50% aqueous hypophosphorous acid (11 mL) and stirred at reflux for 1.5 hr. After cooling, the acetonitrile was removed on a rotary evaporator. The residue was diluted with water (100 mL) and extracted with ethyl acetate (150 mL). The organic layer was washed with water (100 mL), saturated sodium bicarbonate (100 mL) and water (100 mL). The organic layer was dried over sodium sulfate and stripped. The crude product was purified by chromatography on silica (60 g) with 1% ethyl acetate in hexane (2 L). The relevant fractions were stripped and the residue was taken up in ethanol (12 mL) and stirred at 60° C. on a water bath for 30 min. The resulting slurry was allowed to cool overnight. The crystals were collected by filtration, washed with cold ethanol and dried in a vacuum oven at 65° C. to produce pure B4 (0.69 g, 85%).

Provenance & Evidence