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

Temperature

0 °C

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##

1. customTo recover the product
2. additionwater (50 mL) was slowly added with vigorous stirring
3. extractionwas extracted with ether (2×300 mL)
4. washThe ether layer was washed with water (2×150 mL)
5. dry with materialdried over anhydrous MgSO4
6. concentrationconcentrated on a roto-evaporator

ORD record

ord-d73d8b99bf2c49a9a921e71164bfa48f

Source dataset

uspto-grants-1999_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05929194