Toluene → 9,9-Dimethyl-9H-fluorene-2-carbaldehyde

Beteiligte Stoffe

Reaktionsschritte

To a dry 500 mL flask equipped with an argon inlet, a rubber septum, and a distillation head was charged 22.54 g (48.0 mmol) of 9,9-dioctyl-2-bromofluorene and 100 mL of toluene. Toluene was then removed by distillation to dry the flask and starting material. The residue was allowed to cool to room temperature and 250 mL of anhydrous ether was added. The resultant solution was then chilled to −78 ° C. and treated dropwise over 15 minutes with 30.6 mL (49.06 mmol) of 1.6M BuLi in hexane. Upon addition of the butyl lithium solution the reaction mixture initially turned purple and subsequently turned red. Anhydrous DMF (8 mL) was added and the resulting mixture was stirred at −78 ° C. for 1 hour and then warmed up to room and stirred for an additional hour. The mixture was quenched with 50 mL of 10% HCl and transferred into a separatory funnel. The organic phase was washed with 10% HCl (1×), water (2×) and brine (1×), and then dried over MgSO4. Solvent removal afforded 12 g of crude product. Purification by column chromatography (gradient from 96:4 heptanes: EtOAc in heptanes to 90:10 heptanes:EtOAc) afforded 10.2 g of 2-formyl-9,9-dimethylfluorene (49.77% yield). EI-MS: 418 (M+), 362,193 (100). 1H NMR (CDCl3) δ 10.09 (s, 1H), 7.87 (m, 4H), 7.41 (b, 3H), 2.05 (m, 4H), 1.30-1.05 (m, 22H), 0.83 (t, 5H), 0.61 (t, 3H). 13C NMR (CDCl3) δ 192.22, 152.11, 151.55, 147.54, 139.53, 135.39, 130.40, 128.78, 127.10, 123.09, 120.98, 120.91, 119.93, 70.98, 55.32, 40.24, 31.88, 29.92, 29.17, 23.78, 22.59, 14.03.

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