Finkelstein Reaction of 3-Chloro-1-Propanol with Sodium Iodide; 3-Iodo-1-Propanol
Submitted Mar 30, 2012, published Apr 06, 2012
3-Chloro-1-Propanol (98% Purity, Sigma Aldrich)
Acetone (CHROMASOLV®, for HPLC, ≥99.9%, Sigma Aldrich)
Sodium Iodide (ACS reagent, ≥99.5%, Sigma Aldrich)
Diethyl Ether (anhydrous, ≥99.7%, 1 ppm BHT, Sigma Aldrich)
Hexanes (mixture of isomers, anhydrous, ≥99%, Purchased from Sigma Aldrich)
Sodium thiosulfate (ReagentPlus®, 99%)
Sodium Sulfate (ACS reagent, ≥99.0%, anhydrous, granular)
To a 100 mL flask equipped a large stir bar was added the 3-chloro-1-propanol (4.73 g, 0.050 mol) and acetone (50 mL, 1 M in the alcohol). Sodium iodide (37.47 g, 0.250 mol) was then added all at once to the flask . The flask was then equipped with a reflux condenser and, after placing the reaction under a nitrogen atmosphere, was heated to reflux. The mixture was allowed to react for 24 hours. After this time, the now yellow solution was filtered through a medium porosity fritted funnel, eluting with ≈200 mL of acetone into a 500 mL round-bottom flask.1 The solvent was removed by rotary evaporation to afford a dry orange solid. This solid was triturated with a 1:1 v./v. hexanes to Et2O solution (2 X 200mL) and the grey fine precipitate was removed by filtration through a medium porosity fritted funnel.2 The slightly clouded3 yellow-tinged filtrate was washed with ≈100 mL of a 10% w./w. sodium thiosulfate solution, causing the organic layer to become colorless. The organic layer was then washed with ≈100 mL of deionized water, followed by ≈100 mL of brine, and dried with sodium sulfate. The solvent was removed by rotary evaporation to afford pure 3-iodo-1-propanol as a pale yellow oil (7.78 g, 84%).
1H NMR (400 MHz, CDCl3) δ ppm 1.71 (s, 1 H) 2.03 (quin, J=6.30 Hz, 2 H) 3.29 (t, J=6.72 Hz, 2 H) 3.73 (t, J=5.87 Hz, 2 H)
13C NMR (100 MHz, CDCl3) δ ppm 3.25 (-CH2-I) 35.84 (-CH2-) 62.59 (-CH2-OH)
Darwish, T. A.; James, M.; Triani, G.; Hanley, T.L.; Evans, R.A.; Malic, N. J. Am. Chem. Soc., 2010 , 132, 10748.
13C NMR (Iodopropanol C13NMR.jpg)
1H NMR (Iodopropanol HNMR.jpg)
Keywords: alcohols, Alkanes, Alkyl Iodides, Halogens, nucleophilic, substitution