Ozone → 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one

To a solution of 5-prop-2-en-1-yl-2-benzofuran-1(3H)-one (13.5 g, 45.2 mmol) in 200 mL DCM/MeOH (V/V=1:1) was bubbled O3 at −78° C. for 30 min, and N2 was bubbled for another 15 min at −78° C. Then 20 mL of Me2S were added, and the mixture was stirred at r.t. overnight before concentrating to dryness. The residue was dissolved in MeOH (100 mL) and then cooled to 0° C. NaBH4 (5.90 g, 155 mmol) was added in portions. The resulting mixture was stirred at 0° C. for 1 h, then quenched with citric acid (aq.) and extracted three times with EtOAc. The combined organic layers were washed with NaHCO3 (aq.) and brine, dried over anhydrous Na2SO4 and concentrated to dryness. The residue was purified via column chromatography (EtOAc/Petrol Ether=1:5) to give the title compound. 1H-NMR (400 MHz, CDCl3) δ ppm 7.86 (d, J=7.8 Hz, 1H), 7.41 (d, J=7.8 Hz, 1H), 7.38 (s, 1H), 5.29 (s, 2H), 3.92-3.98 (m, 2H), 3.01 (t, J=6.4 Hz, 2H).

1. customN2 was bubbled for another 15 min at −78° C
2. additionThen 20 mL of Me2S were added
3. concentrationbefore concentrating to dryness
4. dissolutionThe residue was dissolved in MeOH (100 mL)
5. temperaturecooled to 0° C
6. stirringThe resulting mixture was stirred at 0° C. for 1 h
7. customquenched with citric acid (aq.)
8. extractionextracted three times with EtOAc
9. washThe combined organic layers were washed with NaHCO3 (aq.) and brine
10. dry with materialdried over anhydrous Na2SO4
11. concentrationconcentrated to dryness
12. customThe residue was purified via column chromatography (EtOAc/Petrol Ether=1:5)

ORD record

ord-ffd53a7125e94dddb2a46090f1936e82

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08952166B2