Reaction #1909801

Reaction equation

9-fluorenone-4-carbonyl chloride

diethylene glycol

triethylamine

→

fluorenone

Solvents

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   Otherequipped with a reflux condenser and a mechanical stirrer
2. 2
   TemperatureThe solution was refluxed for 6 hours
3. 3
   Filtrationfiltered hot
4. 4
   Otherto remove triethylamine hydrochloride salt byproduct
5. 5
   Otherthe filtrate was evaporated to dryness
6. 6
   Otherto obtain the crude product
7. 7
   OtherThe crude product was recrystallized from ethyl acetate with activated charcoal
8. 8
   OtherThe product was dried at 60° C. in a vacuum oven for 6 hours

Procedure

A 10.0 g quantity of 9-fluorenone-4-carbonyl chloride (0.04 mole, obtained from Aldrich Chemicals Co, Milwaukee, Wis. 53201, USA) and 100 ml of tetrahydrofuran (obtained from Aldrich) were added to a 250 ml, 3-neck round bottom flask equipped with a reflux condenser and a mechanical stirrer. The solution was stirred for about ½ hour, and then 2.186 g of diethylene glycol (0.02 mole, obtained from Aldrich) in 50 ml of tetrahydrofuran were added, followed by the addition of 4.17 g of triethylamine (0.04 mole, obtained from Aldrich). The solution was refluxed for 6 hours, filtered hot to remove triethylamine hydrochloride salt byproduct, and the filtrate was evaporated to dryness to obtain the crude product. The crude product was recrystallized from ethyl acetate with activated charcoal. The product was dried at 60° C. in a vacuum oven for 6 hours to yield a third dimeric fluorenone derivative, which was a yellow solid (5.0 g, 47% yield). The product had a melting point of 137° C. A 1H-NMR (300 MHz) spectrum in CDCl3 yielded chemical shifts (ppm) of: 3.88–4.00 (t, 4H); 4.56–4.65 (t, 4H); 7.15–7.34 (m, 4H); 7.40–7.49 (td, 2H); 7.61–7.68 (d, 2H); 7.71–7.77 (dd, 2H); 7.85–7.92 (dd, 2H); 8.20–8.27 (d, 2H).

Source