Iodine → [2-(1-Methylethyl)-2,3-dihydro-1H-isoindol-5-yl]boronic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 5-bromo-2-(1-methylethyl)-2,3-dihydro-1H-isoindole (Intermediate 6, 20 g) in dry tetrahydrofuran (THF) (200 mL) was added to magnesium turnings (3.04 g). To this was added a crystal of iodine and the reaction mixture was heated at reflux for 4 hours. The reaction mixture was cooled to 5° C. and to this was added trimethyl borate (11.17 mL). After 1 hour the reaction was quenched with 2N hydrochloric acid (200 mL). The aqueous phase was extracted with ethyl acetate (3×200 mL), with each extraction was added triethylamine (50 mL). The combined organics were dried over magnesium sulphate and evaporated in vacuo to give a brown foam. This was triturated with TBME (300 mL) and the solid was collected by filtration to give the title compound (9.0 g) as an off-white solid.

Provenance & Evidence