Acetone → 3,3-Dimethylphthalide

Temperature

-78 °C

To a solution of 2-bromobenzoic acid (500 mg, 2.49 mmol) in THF (12.0 ml) cooled at −78° C. was added 2.5M n-BuLi/Hexane (2.0 ml). After stirring for 18 minutes, acetone (0.91 ml, 12.4 mmol) was added. The reaction was allowed to warm to room temperature after 5 minutes at −78° C., and then quenched into 10% HCl aqueous solution (50 ml). The acidic solution was rapidly stirred for 1 hour, and then extracted with EtOAc. The combined organic layers were washed with saturated NaHCO3, brine, dried with anhydrous Na2SO4, and rotary evaporated to give a mixture. Gradient chromatography of the mixture through silica gel column eluted with 20% to 30% EtOAc in hexane afforded 3,3-dimethyl-2-benzofuran-1(3H)-one as a white solid (161 mg, 40%).

1. customquenched into 10% HCl aqueous solution (50 ml)
2. stirringThe acidic solution was rapidly stirred for 1 hour
3. extractionextracted with EtOAc
4. washThe combined organic layers were washed with saturated NaHCO3, brine
5. dry with materialdried with anhydrous Na2SO4
6. customrotary evaporated
7. customto give a mixture
8. washGradient chromatography of the mixture through silica gel column eluted with 20% to 30% EtOAc in hexane

ORD record

ord-10610faab5ea4474aa1b73a49a69fcdb

Source dataset

uspto-grants-2006_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07060844B2