Trimethyl borate → Bicyclo[4.2.0]octa-1,3,5,7-tetraen-3-ylboronic acid

Participants

Reaction Conditions

Reaction Steps

The process described in Example 8 was performed with a preformed Grignard reagent from the reaction of 4-bromobenzocyclobutene (18.3 g, 0.1 mol) with magnesium turnings (2.92 g, 0.12 mol) in THF (80 mL) and trimethylborate (12.5 g, 0.12 mol) in THF (80 mL). To recover the product, the reactor was cooled to 0° C. and water (50 mL) was slowly added with vigorous stirring. The reaction was neutralized with aqueous H2SO4, and was extracted with ether (2×300 mL). The ether layer was washed with water (2×150 mL), dried over anhydrous MgSO4, then concentrated on a roto-evaporator to afford an off-white color solid (14.22 g, 96 percent). 1H and 13C NMR spectra were consistent with the following structure. ##STR12##

Provenance & Evidence