Ethanol → 1-[4-(Benzyloxy)-2-hydroxy-3-nitrophenyl]ethan-1-one

Lithium tert-butoxide (4.06 g) was added to a stirred solution of 1-(2,4-dihydroxy-3-nitrophenyl)ethanone (example 11, step a) (10 g) in DMF (100 mL), under nitrogen, whilst maintaining the internal temperature below 30° C. After stirring for a further 10 minutes at ambient temperature, benzyl bromide (6.03 mL) was added and the mixture stirred for a further 20 h. Further benzyl bromide (3 mL) was added and the mixture stirred for 24 h. The reaction was quenched with water (300 mL), 1M aqueous sodium hydroxide (50 mL) was added and the mixture was washed with diethyl ether (2×300 mL), filtering through Celite to aid separation. The basic solution was cooled in ice/water, acidified with ice cold 2M hydrochloric acid (200 mL) and the resulting precipitate filtered off, washed with water and dried to afford a light brown solid. The solid was slurried with ethanol (100 mL) for 1 h and the solid filtered off, washed with cold ethanol (20 mL), and dried under vacuum at 40° C. to afford the subtitled compound as a light brown solid. Yield 6.8 g.

1. temperatureunder nitrogen, whilst maintaining the internal temperature below 30° C
2. stirringthe mixture stirred for a further 20 h
3. stirringthe mixture stirred for 24 h
4. customThe reaction was quenched with water (300 mL), 1M aqueous sodium hydroxide (50 mL)
5. additionwas added
6. washthe mixture was washed with diethyl ether (2×300 mL)
7. filtrationfiltering through Celite
8. customseparation
9. temperatureThe basic solution was cooled in ice/water
10. filtrationthe resulting precipitate filtered off
11. washwashed with water
12. customdried
13. customto afford a light brown solid
14. filtrationthe solid filtered off
15. washwashed with cold ethanol (20 mL)
16. customdried under vacuum at 40° C.

ORD-Eintrag

ord-72c3c0daf5a34f9f9939fdd126514f65

Quelldatensatz

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08629271B2