Sulfuric Acid → 4,4,5,5,5-Pentafluoro-1-(thiophen-2-yl)pentane-1,3-dione

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Reaction Steps

2-Acetylthiophene (4.3 ml) was dissolved in dry toluene (40 ml). Sodium hydride (60%, 3.2 g) was added slowly and the mixture was stirred for 15 minutes. Ethyl pentafluoropropionate (13.44 g) was added and the stirring was continued overnight. Sulfuric acid (10%, 50 ml) was added and the phases were separated. The organic phase was washed with water (50 ml) and it was evaporated to dryness. The residue was distilled (b.p. 92-94° C./0.15 mbar) to give the product (9.0 g). 1H NMR (CDCl3): 6.50 (s, 1 H); 7.21 (dd, 1H, J=3.9 & 4.9); 7.77 (dd, 1H, J=1.1 & 4.9 Hz); 7.85 (dd, 1H, J=1.1 & 3.9 Hz). IR (film): 1592 (C═O); 1202 (C—F).

Provenance & Evidence