Hydroquinone → 4-Isopropoxyphenol

To a solution of hydroquinone (55.7 g, 0.5 mol) and 2-iodopropane (57.5 g, 0.33 mol) in ethanol was added a solution of potassium hydroxide (78.5 g, 0.5 mol) in water (100 mL). The dark brown solution was then refluxed for 16 hours. The solution was concentrated and the remaining aqueous phase was acidified with 2N HCl and extracted with ethyl acetate (3×200 mL). The combined organic layers were washed with brine, dried over magnesium sulfate and filtered. The filtrate was concentrated to give over 70 g of crude material, which was triturated with methylene chloride and filtered. The filtrate was concentrated and purified on silica gel (5˜35% ethyl acetate in hexane) to give 23.0 g of the title compound (46% yield). 1H NMR (300 MHz, CDCl3) δ ppm 1.30 (d, J=5.88 Hz, 6 H) 4.30-4.50 (m, 1 H) 4.78 (s, 1 H) 6.66-6.86 (m, 4 H). MS (ESI): m/z 151 (M−H).

1. temperatureThe dark brown solution was then refluxed for 16 hours
2. concentrationThe solution was concentrated
3. extractionextracted with ethyl acetate (3×200 mL)
4. washThe combined organic layers were washed with brine
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationThe filtrate was concentrated
8. customto give over 70 g of crude material, which
9. customwas triturated with methylene chloride
10. filtrationfiltered
11. concentrationThe filtrate was concentrated
12. custompurified on silica gel (5˜35% ethyl acetate in hexane)

ORD record

ord-e11a9d2b6ae44b5f9e51b07a08b06194

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08735595B2