Iodine → 2,6-Dimethoxy-4-methoxymethylphenylboric acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of magnesium turnings (97.5 mg, 4.01 mmol) in tetrahydrofuran (0.5 mL) containing a small amount of added iodine, was added approximately a tenth part of a solution of 2-bromo-1,3-dimethoxy-5-(methoxymethyl)benzene (1.0 g, 3.82 mmol) in tetrahydrofuran (1 mL) under a nitrogen atmosphere, and the mixture was heated in an oil bath at 70° C. The heating was terminated upon gentle reflux of the reaction mixture and fading of the iodine color. To continue the reflux, the remaining solution of 2-bromo-1,3-dimethoxy-5-(methoxymethyl)benzene in tetrahydrofuran was added dropwise to the reaction mixture. Upon completion of the dropwise addition, the reaction mixture was further heated to reflux for 1 hour and then cooled to room temperature. The reaction mixture was then added dropwise to an ice-cooled solution of trimethyl borate (0.57 mL, 4.97 mmol) in tetrahydrofuran (0.5 mL). Upon completion of the dropwise addition and stirring for 40 minutes while cooling with ice, the mixture was stirred overnight at room temperature. An aqueous ammonium chloride solution and methanol were then added to the reaction mixture. Quantitation by liquid chromatography confirmed that the title compound had been obtained at an 89% yield.

Provenance & Evidence