PREPARATION OF ASPIRIN
EXPERIMENT A
PREPARATION OF ASPIRIN
Abstract
This report gives a detailed account of the experimental preparation of aspirin in a laboratory environment as well as some basic industrial background on the product. It also contains information about safety precautions put in place to ensure the safety of the team who carried out the experiment. All results obtained have been included as well as a detailed analysis of what they represent alongside any improvements to the method used.
Introduction
The aim of this experiment was to successfully prepare a sample of 2-acetoxybenzoic acid [1], commonly known as aspirin, through the reaction of salicylic acid with acetic anhydride under acidic conditions provided by sulphuric acid. Once the reaction was completed the samples’ yield and melting point were determined for comparison to industrial perimeters. The equation below outlines the overall reaction between salicylic acid and acetic anhydride. Note that acetyl salicylate is a synonym of aspirin and acetic acid is a by-product.
Aspirin is one of the safest pain relievers on the market, its great success as a non-prescription drug also comes down to its affordable price as well as its other medicinal features such as having an anti-inflammatory affect. 80 million aspirin tablets [3] are consumed annually in the US alone therefore it must be manufactured at a grand scale. The solubility of aspirin in water at 20°C is 3mg/ml [4]; however this value can change with a change in temperature. [5] At higher temperatures aspirin molecules have a higher kinetic energy and therefore collide with each other as well as water molecules more often, resulting in an increase in solubility. On the other hand, at lower temperatures aspirin molecules have lower kinetic energy and this allows them to bind together, also known as ‘falling out’ of solution or crystallisation.
The main variations between the method used in the experiment and the common industrial methods
PREPARATION OF ASPIRIN
Abstract
This report gives a detailed account of the experimental preparation of aspirin in a laboratory environment as well as some basic industrial background on the product. It also contains information about safety precautions put in place to ensure the safety of the team who carried out the experiment. All results obtained have been included as well as a detailed analysis of what they represent alongside any improvements to the method used.
Introduction
The aim of this experiment was to successfully prepare a sample of 2-acetoxybenzoic acid [1], commonly known as aspirin, through the reaction of salicylic acid with acetic anhydride under acidic conditions provided by sulphuric acid. Once the reaction was completed the samples’ yield and melting point were determined for comparison to industrial perimeters. The equation below outlines the overall reaction between salicylic acid and acetic anhydride. Note that acetyl salicylate is a synonym of aspirin and acetic acid is a by-product.
Aspirin is one of the safest pain relievers on the market, its great success as a non-prescription drug also comes down to its affordable price as well as its other medicinal features such as having an anti-inflammatory affect. 80 million aspirin tablets [3] are consumed annually in the US alone therefore it must be manufactured at a grand scale. The solubility of aspirin in water at 20°C is 3mg/ml [4]; however this value can change with a change in temperature. [5] At higher temperatures aspirin molecules have a higher kinetic energy and therefore collide with each other as well as water molecules more often, resulting in an increase in solubility. On the other hand, at lower temperatures aspirin molecules have lower kinetic energy and this allows them to bind together, also known as ‘falling out’ of solution or crystallisation.
The main variations between the method used in the experiment and the common industrial methods
References: and Acknowledgements [1] – International Union of Pure and Applied Chemistry (IUPAC) [2] – http://www.britannica.com/EBchecked/topic/519177/salicylic-acid [3] – http://www.madehow.com/Volume-1/Aspirin.html [4] – Pharmacokinetic Solubility And Dissolution Profile of Non-Steroidal Anti-Inflammatory Drugs [5] – http://chemistry.about.com/od/demonstrationsexperiments/ss/aspirin_5.htm [6] – http://njcmr.njit.edu/distils/lab/aspirins/nap4.html [7] – Handbook of Chemistry and Physics