Dichloromethane → (4-Methoxy-2-nitrophenyl)boronic acid

Participants

Reaction Steps

To a solution of 1-iodo-4-methoxy-2-nitrobenzene (5 g, 17.9 mmol) in THF (50 mL) cooled to −60° C. was added phenylmagnesium bromide (10.4 mL, 25 wt %, 19.7 mmol) which gave a dark red solution. Trimethylborate (2.4 mL, 21.5 mmol) was then added dropwise. After 30 min, the reaction was quenched with 1 N HCl (40 mL) and extracted with ether. The organic layer was then dried over Na2SO4 and the solvent was removed in vacuo to give a dark brown oil which was tritrated with DCM to yield (4-methoxy-2-nitrophenyl)boronic acid as grey solid. A portion of this material (1.57 g, 8 mmol) was then taken up in DME (1 mL) and 1-bromo-4-iodo-2-methoxybenzene (C1, step 1) (2.5 g, 8 mmol), CsF (2.73 g, 18 mmol), and tetrakistriphenylphosphine palladium (0.92 g, 0.8 mmol) under nitrogen. The mixture was then heated to 100° C. for 18 h. The mixture was then extracted with water and EtOAc. The organic layer was then dried over Na2SO4 and the solvent was removed in vacuo. The crude material was then purified on silica (gradient elution, 3-50% EtOAc/hexanes) to yield the title compound as a yellow solid.

Provenance & Evidence