Formation of pentafluorophenol sulfonate esters from sulfonyl chlorides; pentafluorophenyl sulfonate esters

Jonathan Wilden ([email protected]),
A contribution from the Caddick Group, Sussex

Chemicals Used
2-chloroethanesulfonyl chloride (Avocado) pentafluorophenol (Lancaster) triethylamine (Avocado) THF (distilled) or DCM (distilled)

Procedure
A solution of the sulfonyl chloride (1.0 g, 0.64 mL, 6.1 mmol) in THF (30 mL) or DCM (30 mL) was cooled to -15 ^oC under an inert atmosphere. To this solution was added triethylamine (2.5 mL, 2.6 g, 25 mmol) dropwise so that the temperature did not rise above 0 ^oC. A solution of pentafluorophenol (1.1 g, 6.1 mmol) in THF (10 mL) or DCM (10 mL) was added dropwise so that the temperature did not rise above 0 ^oC. The mixture was allowed to stir for a further 20 minutes after which time the cooling bath was removed and the reaction allowed to warm to RT over 3h. The reaction was diluted with DCM (30 mL) and washed with 2M HCl (3 x 30 mL), 2M sodium carbonate solution (3 x 30 mL) and water (2 x 30 mL). The organic fraction was dried (MgSO₄), filtered, and the solvent removed from the filtrate in vacuo. The crude product was purified by flash column chromatography (10% Ether/Petrol) to yield the PFP sulfonate ester as a yellow oil (0.99 g, 3.6 mmol, 59%)

Author's Comments
This reaction is usually reliable on a 1-10 g scale providing that the temperature is controlled fairly carefully. If the temperature rises above 10 ^oC during the exothermic reaction then darkening of the solution is observed and polymeric materials formed which give a lowering of yield.

Data
¹H NMR (CDCl₃, 300 MHz) 6.80 (1H, dd, CH=), 6.49 (1H, d, =CHH), 6.38 (1H, d, =CHH). m/z (EI +ve) 274 (M⁺).

Lead Reference
Caddick, S.; Wilden, J. D.; Bush, H. D.; Wadman, S. N.; Judd, D. B.; Org. Lett.; 2002; 4(15); 2549-2551.

Other References

This page has been viewed approximately 911 times since records began.

Get CDX file (Choose "Open this file from its current location" TWICE)

SyntheticPages^TM are for use exclusively by those with training and experience in synthetic chemistry. While contributors are asked to identify hazards and to use methods designed to reduce risk, no formal hazard or risk assessments are included, and these procedures must be conducted at one's own risk. SyntheticPages, its editors, owners and associates do not warrant or guarantee the safety of individuals using these procedures and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures herein. Copyright ©2004 Synthetic Pages

Comment on this page!