Hydrochloric Acid → 4-Hydroxy-6-(4-methoxy-phenyl)-2-oxo-2H-chromene-3-carboxylic acid methyl ester

Participants

Reaction Steps

To a mixture of 6-bromo-4-hydroxy-2-oxo-2H-chromene-3-carboxylic acid methyl ester (150 mg, 0.5 mmol; example 2-b) in dimethoxyethane (DME) was added 4-methoxyphenylboroic acid (92 mg, 0.6 mmol), tetrakis(triphenylphosphine)palladium(0) (58 mg, 0.05 mmol) and 2N aq Na2CO3 (0.62 mL). The resulting mixture was purged with N2 for 1 min and heated to reflux for 2 h. Reaction mixture was diluted with water (50 mL) and acidified by 1 N aq HCl to pH=3-4. Precipitate was collected and dissolved in EtOAc. Insoluble was filtered off and the filtrate was dried over MgSO4, filtered, and concentrated. The crude product was triturated with MeOH (10 mL) and filtered. Resulting solid was dried in vacuo to give the title compound (112 mg). MS ESI(+) m/e: 327 (M+1).

Provenance & Evidence