Benzyl formate → 9-Formyl-2,7-fluorenedicarboxylic acid dibenzyl ester

Beteiligte Stoffe

Reaktionsschritte

In a dry argon-purged flask, 2,7-fluorenedicarboxylic acid dibenzyl ester (3.0 g, 0.0065 mol) was dissolved in anh. THF (60 mL) at room temperature. Benzyl formate (4.2 mL, 0.035 mol, stored over anhydrous K2CO3) was added followed by addition of potassium tert-butoxide 95% (2.7 g, 0.023 mol). The reaction was stirred for three hours then the reaction was quenched with the addition of water and acidified with HCl to pH 2. The organic solvent was partially evaporated at reduced pressure. The product was twice extracted with ethyl acetate (600 mL then 200 mL). The combined organic layers were washed three times with brine, dried over sodium sulfate, filtered and evaporated to dryness. The crude product was washed with hexanes and methanol (1.9 g, 60%). 1H-NMR (d6-DMSO): δ (ppm) 11.9 (s, ˜1H, formyl); 8.8 (s, 1H, Ar); 8.5 (s, 1H, Ar); 8.4 (s, 1H, Ar); 8.2 (m, 2H, Ar); 7.9 (m, 2H, Ar); 7.5-7.4 (m, 10H, Bz); 5.4 (s, 4H, Ar).

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