The Williamson ether synthesis Miami University（威廉姆森醚合成迈阿密大学）.pdf

The Williamson ether synthesis The Williamson ether synthesis is an organic reaction, forming an ether from an alkyl halide and an alcohol. This reaction was developed by Alexander Williamson in 1850. It involves the reaction of an alkoxide ion with a primary alkyl halide via an SN2 reaction. The Williamson reaction is widely used in both laboratory and industrial synthesis, and remains the simplest and most popular method of preparing ethers. Both symmetrical and asymmetrical ethers are easily prepared. The reaction for this week: an example of a Williamson ether synthesis acetaminophen ethyl iodide phenacetin starting material reagent product Phenacetin may be synthesized as an example of the Williamson ether synthesis The first synthesis of phenacetin was reported in 1878 by Harmon Morse. Procedure 1. Weigh an Extra-Strength Tylenol tablet. Pulverize the tablet with mortar and pestle. Weigh out 0.22 g and place it in a dry 15-ml round-bottom flask along with 0.28 g of finely pulverized K2CO3 (mortar and pestle) and 3.0 mL of butanone. Carefully add 0.28 mL of ethyl iodide with a syringe. 2. Add a stir bar; attach a microscale water-cooled condenser to the flask. Heat the mixture under reflux directly on a hot plate at medium setting for 1 hour. In the meantime, obtain the IR of acetaminophen. 3. Turn off the heat. Allow the mixture to cool down. Add 4 mL of water to the flask and transfer its contents to a 16 x 125 mm test tube with a screw cap. Rinse round-bottom flask 4 times with 1 mL of tert-butyl methyl ether (BME) and add the rinsings to the test tube. 4. Cap the test tube and shake the layers. Vent to release the pressure by unscrew the cap momentarily. With a Pasteur pipet r