Azobisisobutyronitrile → 1-(Bromomethyl)-3-(1,1,2,2-tetrafluoroethoxy)benzene

To a solution of 3-(1,1,2,2-tetrafluoroethoxy)toluene (25 g, 0.12 mol) in ethyl acetate (400 ml) were added N-bromosuccinimide (21.4, 0.12 mol) and 2,2′-azobisisobutyronitrile (0.2 g) and the mixture was heated under reflux for 2.5 hrs. The reaction solution was concentrated under reduced pressure, and diethyl ether and hexane were added. Insoluble material was removed, and washed with diethyl ether. The filtrate was evaporated under reduced pressure to give 3-(1,1,2,2-tetrafluoroethoxy)-1-bromomethylbenzene. To a solution of ethyl 3-(4-bromophenyl)-3-oxopropanoate (27.1 g, 100 mmol) in dimethoxyethane (150 ml) was added sodium hydride (4.0 g, 60% in oil, 0.1 mol) under ice-cooling and the mixture was stirred for 1 hr. A solution of 3-(1,1,2,2-tetrafluoroethoxy)-1-bromomethylbenzene obtained above in dimethoxyethane (20 ml) was dropwise added and the mixture was stirred at room temperature for 15 hrs. To the reaction solution was added water (300 ml) and the mixture was extracted with ethyl acetate (200 ml×2). The extract was washed with water, dried over anhydrous magnesium sulfate and evaporated under reduced pressure. The residue was purified by silica gel chromatography (hexane:toluene=1:2-1:5). Crystallization from hexane gave the objective substance (21.1 g, 44%).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 2.5 hrs
3. concentrationThe reaction solution was concentrated under reduced pressure, and diethyl ether and hexane
4. additionwere added
5. customInsoluble material was removed
6. washwashed with diethyl ether
7. customThe filtrate was evaporated under reduced pressure

ORD record

ord-21e6322e3f0f496e97efad39c4fb5021

Source dataset

uspto-grants-2006_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06982348B2