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. Ethanol was removed and the aqueous phase was acidified with 2N HCl and extracted with ethyl acetate (3×200 mL). The combined organic layers were washed with brine, dried (MgSO4) and filtered. The filtrate was concentrated in vacuo to give over 70 g of crude material, which was triturated with dichloromethane and filtered. The filtrate was concentrated and purified on silica gel (5˜35% ethyl acetate/hexane) to give 23.0 g of product as a brown oil (46% yield). 1H NMR (300 MHz, CDCl3) δ ppm 1.30 (d, J=5.88 Hz, 6H) 4.30-4.50 (m, 1H) 4.78 (s, 1H) 6.66-6.86 (m, 4H). MS (ESI): m/z 151 (M−H). 1H NMR (300 MHz, CDCl3) δ ppm 8.31 (d, J=1.84 Hz, 1H) 7.99 (dd, J=8.46, 1.84 Hz, 1H) 7.77 (d, J=9.19 Hz, 1H) 7.20-7.34 (m, 2H) 6.89-7.01 (m, 2H) 4.48-4.62 (m, 1H) 2.65 (s, 3H) 1.37 (d, J=5.88 Hz, 6H). MS m/z (DCI) 405.1 (M+H)+.

1. temperatureThe dark brown solution was then refluxed for 16 hours
2. customEthanol was removed
3. extractionextracted with ethyl acetate (3×200 mL)
4. washThe combined organic layers were washed with brine
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. concentrationThe filtrate was concentrated in vacuo
8. customto give over 70 g of crude material, which
9. customwas triturated with dichloromethane
10. filtrationfiltered
11. concentrationThe filtrate was concentrated
12. custompurified on silica gel (5˜35% ethyl acetate/hexane)

ORD-Eintrag

ord-f95e10e93cbd4c03a61ef024963e3a76

Quelldatensatz

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08207350B2