Reaktion #89594

Reaktionsgleichung

N-bromosuccinimide

VAZO

N2

Bromobenzocyclobutene

→

1-bromo-bromobenzocyclobutene

Ausbeute 93.0%

Lösungsmittel

chlorobenzene

chlorobenzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThen the reaction mixture was heated to 133° C.
2. 2
   Temperatur(mild reflux)
3. 3
   TemperaturThe mixture was then cooled to room temperature overnight
4. 4
   Sonstigechlorobenzene was removed by vacuum evaporation
5. 5
   ExtraktionThe crude product was extracted with hexane
6. 6
   SonstigeAfter removal of hexane

Vorschrift

Bromobenzocyclobutene (91.5 g, 0.5 mol) and chlorobenzene(anhydrous, 2500 mL) were charged into a four-neck 5 L flask equipped with mechanical stir, condenser, N2 (in and outlet) and thermometer. The reaction mixture was heated to 120° C., and N-bromosuccinimide (111.3 g, 0.625 mol) was gradually charged over 30 min., followed by slowly feeding a mixture of a free radical azo compound source (VAZO™ 68) (14.0 g, 0.05 mol) and chlorobenzene (500 mL) over 30 min. Then the reaction mixture was heated to 133° C. (mild reflux) and kept at that temperature for 6 hr. The mixture was then cooled to room temperature overnight, and chlorobenzene was removed by vacuum evaporation. The crude product was extracted with hexane. After removal of hexane, 1-bromo-bromobenzocyclobutene (1-Br-BrBCB) (80-85° C/0.35 torr, 90 g, ca. 93% purity) was obtained by vacuum distillation.

Quelle