Toluene → Methyl 2-amino-5-phenylbenzoate

Participants

Reaction Steps

To a suspension of 5-bromo-2-amino-benzoic acid methyl ester (3.0 g, 13,04 mmol), tetrakis(triphenylphosphine)palladium(0) (0.5 g, 0.44 mmol), toluene (40 ml) and 2 N aqueous sodium carbonate (14.8 ml) was added a solution of phenylboronic acid (2.2 g, 17.73 mmol) in methanol (10 ml) at room temperature. The resulting reaction mixture was heated at reflux temperature for 4 h. cooled and diluted with water (50 ml). The insoluble matter was filtered off and the phases were separated. The aqueous phase was extracted with ethyl acetate (100 ml) and the combined organic phases were washed with water (2×80 ml), diluted aqueous ammoniac (80 ml) and saturated aqueous sodium chloride (80 ml). The organic phase was dried (MgSO4), filtered and evaporated in vacuo affording 3.4 g of crude 4-amino-biphenyl-3-carboxylic acid methyl ester which was purified on silicagel (1 l) using a mixture of ethyl acetate and heptane (1:3) as eluent. Pure fractions were collected and evaporated in vacuo affording 2.7 g (91%) of 4-amino-biphenyl-3-carboxylic acid methyl ester.

Provenance & Evidence