Potassium Phosphate, Tribasic → HCID 67315543, compound

Participants

Reaction Conditions

Reaction Steps

1.40 g (4.74 mmol) of 5-(3-bromo-phenyl)-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester (6′) (and ethyl ester) was dissolved in 15 ml of toluene and 1.6 ml of H2O. Then 1.54 g (9.49 mmol) of benzo[b]furan-2-boronic acid, 5.42 g (25.52 mmol) of K3PO4, 0.29 g (1.04 mmol) of tricyclohexylphosphine and 0.117 g (0.52 mmol) of palladium-II-acetate were added. The reaction mixture was degassed (argon) several times at each addition. The reaction was heated (100° C.) for 24 h. At RT, the mixture was partitioned between chilled water/EtOAc (3×). The organic phases were washed with water, with aqueous sat. NaHCO3, dried (Na2SO4), filtered (black palladium complex stayed with Na2SO4) and evaporated. Then the residual product was dissolved in hot CH2Cl2 and crystallized at RT. It was filtered to give 0.918 g (58%) of 5-(3-benzofuran-2-yl-phenyl)-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester as white powder. MS: 332.2 (M+).

Provenance & Evidence