Reaction #2175456

Reaction equation

2,7-fluorenedicarboxylic acid dibenzyl ester

Benzyl formate

potassium tert-butoxide

→

9-formyl-2,7-fluorenedicarboxylic acid dibenzyl ester

Solvents

THF

Conditions

Workup

1. 1
   OtherIn a dry argon-purged flask
2. 2
   Otherthe reaction was quenched with the addition of water
3. 3
   OtherThe organic solvent was partially evaporated at reduced pressure
4. 4
   ExtractionThe product was twice extracted with ethyl acetate (600 mL
5. 5
   WashThe combined organic layers were washed three times with brine
6. 6
   Dryingdried over sodium sulfate
7. 7
   Filtrationfiltered
8. 8
   Otherevaporated to dryness
9. 9
   WashThe crude product was washed with hexanes and methanol (1.9 g, 60%)

Procedure

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).

Source