Cycloheptanone → 4-[(4-Bromophenyl)(cycloheptylidene)methyl]phenol

Beteiligte Stoffe

Reaktionsschritte

To a three-neck round-bottomed flask equipped with a magnetic stir bar, reflux condenser, rubber septum, and two nitrogen inlets, was added zinc powder (13.0 g, 199 mmol) followed by anhydrous THF (200 mL). To the stirred suspension was slowly added TiCl4 (11.0 mL, 19.0 g, 100.0 mmol) via syringe (caution: vigorous fuming). The reaction mixture was heated at reflux for 2 h. To the refluxing reaction mixture was added a solution of cycloheptanone (9.0 mL, 8.56 g, 76.3 mmol) and (4-bromophenyl)(4-hydroxyphenyl)methanone (2) (6.91 g, 24.9 mmol) in THF (200 mL) slowly via syringe. The reaction mixture was heated at reflux under a nitrogen atmosphere with stirring for 2 h. The oil bath was removed and the reaction mixture was allowed to cool to room temperature. The three neck round-bottomeded flask was equipped with an addition funnel and water (150 mL) was slowly added to the reaction mixture followed by 10% aqueous K2CO3 (150 mL). The reaction mixture was filtered through a pad of Celite. The pad was washed with EtOAc. The filtrate was transferred to a separatory funnel and the layers were separated. The organic phase was washed with brine, dried over MgSO4, filtered, and the filtrate was concentrated to give the crude product as an orange oil. The crude product was partially purified by flush chromatography on silica gel with hexanes:EtOAc (100:0 to 95:5) to give a solid. The solid was triturated with hexanes and filtered to give 6.3 g (71%) of compound (9) as an off-white solid. 1H NMR (400 MHz, DMSO-d6): δ 1.50 (m, 8H), 2.20 (m, 4H), 6.66 (d, J=8.5 Hz, 2H), 6.89 (d, J=8.4 Hz, 2H), 7.04 (d, J=8.4 Hz, 2H), 7.45 (d, J=8.4 Hz, 2H), 9.30 (s, 1H).

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