4-Hydroxybenzaldehyde → 4-(2,2,2-Trifluoroethoxy)benzaldehyde

Beteiligte Stoffe

Reaktionsschritte

Potassium hydroxide pellets (85%, 13.2 g, 0.2 mol) are added to 4-hydroxybenzaldehyde (24.4 g, 0.2 mol) and 18-crown-6 (2.6 g, 5% mol) in diglyme (150 mL). The red reaction mixture is stirred for 16 hours at room temperature and then a solution of 2,2,2-trifluoroethyl-p-toluenesulfonate (50.8 g, 0.2 mol) in diglyme (100 mL) is added over 30 minutes, after which the mixture is allowed to stir at room temperature for 45 minutes. The resulting suspension is then heated at reflux for 24 hours. The mixture is cooled to 10° C. and poured into ice water (1300 mL). The organic materials are extracted with ether (4×200 mL), and the extracts washed with 5% sodium hydroxide (2×100 mL), water (2×100 mL) and saturated sodium chloride (1×100 mL), and dried over MgSO4. Evaporation of the ether gives an amber oil which is purified by high performance liquid chromatography using silica gel on a Waters 500 unit and 50:50 hexane and methylene chloride as eluant to give 12.3 g of the title product with Rf 0.25. Anal. Calcd for C9H7F3O2 (204.15) C, 52.94; H, 3.43. Found C, 52.04; H, 3.59.

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