Aims: To determine how phenacetin from acetamidophenol (known as paracetamol) is synthesized using Sodium Ethoxide Iodine, which is the Williamson Ether synthesis.
Experimental: Sodium metal was patted dry to remove any oil and was cat into small pieces. A dry 100cm3 round bottom flask was placed on a cork ring, on a balance and tarred sodium metal (0.6g) was placed into the flask. The flask was then attached to the dry reflux condenser and industrial methylated spirits (IMS, 15cm3) was added. Once all of the sodium has dissolved the solution was cooled to room temperature and the para-acetamidophenol (3.5g) was added. Ethyl iodine (3.0cm3) was slowly introduced to the mixture through the top of the condenser and the resulting in the mixture was boiled at reflux temperature for 20 minutes and was placed in a rotary evaporator to remove any excess solvent. Distilled water (40cm3) was added to the mixture and the flask was placed in ice until crystals were formed. The crude product was filtered using vacuum filtration the filtrates were washed with very little cold water and were left dry as much as possible.
The product was placed in a beaker, and enough aqueous methylated spirit (IMS) was added whilst the mixture was heated to dissolve the product. The mixture was then left to cool and was placed in ice to aid crystallization. The product was vacuum filtrated after a few minutes of standing in ice and the crystals were collected and dried in a vacuum oven at 40 degrees celsius. The mass of the crystals was calculated and the melting point was determined.
Product appearance: white shiny flake like crystals.
Weight of product and watch glass: 39.14g
Weight of empty watch glass: 36.64g
Weight of Phenacetin: 3.50g
Percentage yield (%) : Theoretical yield= moles starting material x RMM of product
% yield= actual yield/theoretical yield x 100%: para-acetamidophenol is the