Cyclohexanone → 4-[(4-Bromophenyl)(cyclohexylidene)methyl]phenol

Beteiligte Stoffe

Reaktionsschritte

To a 3-neck round-bottomed flask were added zinc powder (1.96 g, 30 mmol) followed by anhydrous THF (40 mL). To the stirred suspension was slowly added, via syringe, TiCl4 (1.6 mL, 2.77 g, 14.6 mmol) at room temperature. The reaction mixture was heated at reflux with stirring under a nitrogen atmosphere for 2 h. To the refluxing reaction mixture was added a solution of (4-bromophenyl)(4-hydroxyphenyl)methanone (2) (1.1 g, 3.61 mmol) and cyclohexanone (1.1 mL, 1.04 g, 10.6 mmol) in anhydrous tetrahydrofuran (40 mL). The stirred reaction mixture was heated at reflux under a nitrogen atmosphere for 2 h. The oil bath was removed and the reaction mixture was allowed to cool to room temperature. To the reaction mixture was slowly added water (24 mL) followed by 10% aqueous K2CO3 (24 mL). The reaction mixture was filtered through a pad of Celite and the pad washed with EtOAc. The filtrate was transferred to a separatory funnel with the aid of water and EtOAc and the layers were separated. The organic phase washed with brine, dried over MgSO4, filtered, and the filtrate was concentrated in vacuo to give the crude product. The crude product was purified by flash chromatography on silica gel with hexanes:EtOAc (100:0 to 60:40) to give 1.17 g (95%) of compound 6 as an off-white solid. 1H NMR (400 MHz, DMSO-d6): δ 1.52 (m, 6 H), 2.12 (m, 4 H), 6.65 (d, J=8.4 Hz, 2 H), 6.82 (d, J=8.4 Hz, 2 H), 6.97 (d, J=8.3 Hz, 2 H), 7.44 (d, J=8.3 Hz, 2 H), 9.32 (s, 1 H). HRMS (EI) Calcd for C19H19BrO: 342.0619 (M+). Found: 342.0627.

Herkunft & Nachweise