2,4-Dimethoxybenzeneboronic acid → 3-(2,4-Dimethoxyphenyl)-7-methoxy-4H-1-benzopyran-4-one

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Reaction Steps

A solution of 13 (4.0 g, 15.8 mmol) and 2,4-dimethoxy benzeneboronic acid (3.4 g, 19.0 mmol) and Pd(Ph3)4 (0.79 g) in toluene/EtOH (50 mL/5 mL) and 2M Na2CO3 aq. (30 mL) was heated to reflux. After 5 h, the reaction was cooled and the organic layer dried over MgSO4, concentrated and chromatographed on silica gel (EtOAc/hexanes 3:7 to EtOAc/hexanes 1:1) to yield 14 as a solid which was triturated with MeOH to give a tan solid.

Provenance & Evidence