1,2-Dibromoethane → 1-(3-Chloro-2-methylphenyl)cyclohexanol

Beteiligte Stoffe

Reaktionsschritte

96 g (4 moles) of Mg turnings in 60 ml of absolute tetrahydrofuran (THF) are initially taken under a nitrogen atmosphere. 1 ml of 1,2-dibromoethane is added at 65° C., after which a solution of 644 g (4 moles) of 2,6-dichlorotoluene in 1.5 1 of absolute THF is added dropwise in the course of 21/4 hours. Thereafter, the mixture is stirred for 4 hours under reflux and cooled to room temperature, and 352.8 g (3.6 moles) of cyclohexanone in 250 ml of absolute THF are added under nitrogen. When the reaction is complete, the Grignard reaction mixture is worked up in an aqueous medium in a conventional manner and the solvent is substantially removed by distillation under reduced pressure. The residue is subjected to incipient distillation (30°-107° C./0.27 mbar). The remaining crude product (676 g), which contains as much as 90% of 1-(3'-chloro-2'-methylphenyl)-cyclohexanol, can be further purified by column chromatography using toluene as the mobile phase.

Herkunft & Nachweise