Benzyl Bromide → 3-Benzyloxy-4-bromonitrobenzene

A mixture of 27.4 g (125.6 mmol) of 2-bromo-5-nitrophenol, 26 g (188.4 mmol) potassium carbonate, and 250 mL DMF were stirred 15 min at room temperature. 16.4 mL (138 mmol) of benzyl bromide was added in one portion to the reaction mixture and the mixture was heated to 90° C. TLC analysis indicated complete reaction, so the reaction mixture was cooled to 5° C. in an ice/water bath, filtered and concentrated. 300 mL water was added to the reaction mixture and the black precipitate was filtered and air dried. The crude product was taken up in dichloromethane and purified over silica eluting with 35% hexanes in dichloromethane, to give 2-bromo-5-nitro-O-benzylphenol 35.5 g (115.2 mmol, 91.7%) as an ivory solid. 1H NMR (400 MHz) CDCl3 7.78 (s, 1H), 7.72 (s, 2H), 7.46-7.48 (m, 2H), 7.38-7.42 (m, 2H), 7.32-7.35 (1H), 5.23 (s, 2H).

1. temperaturethe mixture was heated to 90° C
2. customreaction
3. temperatureso the reaction mixture was cooled to 5° C. in an ice/water bath
4. filtrationfiltered
5. concentrationconcentrated
6. addition300 mL water was added to the reaction mixture
7. filtrationthe black precipitate was filtered
8. customair dried
9. custompurified over silica eluting with 35% hexanes in dichloromethane

ORD-Eintrag

ord-20403895d3254fbeb45c9f60e1fb9c74

Quelldatensatz

uspto-grants-2005_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06875765B2