The Synthesis Of Phenacetin From p-Acetamidophenol

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CH1751B – EXPERIMENT 15

The Synthesis Of Phenacetin From p-Acetamidophenol

Introduction:

“Phenacetin is an analgetic and an antipyretic reagent which acts in the body by temporaririly inhibiting prostaglandin synthesis in the central nervous system”.

Aim:

  • To synthesise Phenacetin from p-Acetamidophenol and purify it by recrystallisation.
  • Analyse purity of Phenacetin produced, by comparing the melting point with the literature values, the appearance and the Infrared Spectrum.

Method:

Sodium metal (0.6g, cut into small pieces) was cautiously placed into a dry 100cm3 round flask by taking the flask to the “sodium” balance and placing the sodium directly into the flask. A dry reflux condenser was attached and industrial methylated spirits (IMS, 15cm3) was added. A vigorous reaction occurred for 5-10 minutes under reflux until most of the sodium had dissolved. Once the solution had cooled 3.8g of p-acetamidophenol was added. Through the top of the condenser ethyl iodide (3.0cm3) was introduced to the pale green mixture and the mixture boiled at reflux temperature (20-25˚). Ethyl iodide was obtained from a burette in the fume hood few minutes before its use, due to its flammable nature and harmful vapour. A darkening green colouration occurred while p-acetanilide dissolved changing through to brown and then yellow.

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Once the reflux was completed 40cm3 of water was added and the flask was left in ice for a few minutes to cool. The crude product then was filtered and washed with a little cold water and stored in a desiccator until the following week for recrystallisation.

The following week the product was recrystallised from aqueous spirit (1:1 volume) and dried in the vacuum oven at 40oC. The yield and melting point of the product was determined and the percentage yield was calculated. An IR spectrum of the product was recorded and all the remaining samples were handed in ...

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Could have been presented a bit more tidy with different font sizes in places and hard to read bulk paragraphs in places which should have be formatted as suggested above. Spelling, grammar and punctuation all to a good standard.

The candidate uses a good introduction which concisely sets out what they're going to do and the uses of the product in the wider society. The method should really be bullet pointed with the observations next to them so it is clearer to read, although you can decipher how to carry out the experiment from the block of text provided. The diagram of the reaction and the chemical equation are all correct. The results and discussion show the experiment was successful, and show a deep scientific analysis and understanding of the experiment. Equations are correct, and decimal places are consistent. The candidate provided a well thought out discussion about why the results showed what they did. The conclusion is adequate and succinct.

The response to the question is done well throughout based on analysis, correct calculations and the depth of discussion. The main things that need work are just the structure