Hydrochloric Acid → 4-(3-Hydroxypropyl)benzene-1,3-diol

Temperature

65 °C

To a stirred solution of 7-hydroxycoumarin (7.0 g, 43.2 mmol ) in anhydrous THF (200 mL ) at rt under argon was added Lithium borohydride (2M, 65.8 mL, 129.6 mmol, 3.0 eq) solution in THF dropwise. Anhydrous methanol (1.0 mL) was added as catalyst to the reaction mixture. The mixture was heated at 65° C. for 17 h. The reaction mixture was then cooled to ambient temperature. Saturated ammonium chloride solution (40 mL) was added dropwise to the solution, followed by 1N HCl solution (40 mL). The mixture was extracted with ethyl acetate (2×100 mL). The combined organic extracts were dried (Na2SO4), filtered, and evaporated in vacuo. The residue was purified on silica gel (flash column chromatography) eluting with 30% ethyl acetate-hexane to provide the desired product as white solid (3.05 g, 42%). 1H-NMR (CD3CN) δ 6.91 (d, 1H), 6.29 (s, 1H), 6.28 (d, 1H), 3.51 (t, 2H), 2.56 (t, 2H), 1.73 (m, 2H). MS GC-MS (M+=168).

1. temperatureThe reaction mixture was then cooled to ambient temperature
2. extractionThe mixture was extracted with ethyl acetate (2×100 mL)
3. dry with materialThe combined organic extracts were dried (Na2SO4)
4. filtrationfiltered
5. customevaporated in vacuo
6. customThe residue was purified on silica gel (flash column chromatography)
7. washeluting with 30% ethyl acetate-hexane

ORD record

ord-2fc1d2009a2d44c289d36fbe7124f4df

Source dataset

uspto-grants-2008_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07384947B2