Abstract:The purpose of this experiment was to synthesise fatty ethanolamide from lauric acid and 2-aminoethanol and determine the melting of the fatty ethanolamide. The experiment was carried out in a fume cupboard. The melting point was found to be 76-80C where it started to melt at 76C and melted completely at 80C. The percentage yield was calculated to be 101.35%. This indicates an error due to impurities present or human error.

Introduction:The aim of this experiment was to produce fatty ethanolamide from reacting lauric acid with 2-aminoethanol. The melting point and percentage yield would be determined/calculated. The reaction is shown below:

C11H23COOH + CH2(OH).CH2NH2 C11H23CONH.C2H4OH + H2O

The major product of the experiment was fatty ethanolamide. This is because the NH2 functional group on the 2-aminoethanol is more reactive than the OH group which is also attached on the 2-aminoethanol. Distillation was carried out to separate the major product (fatty ethanolamide) from the minor product (water). This process is also performed to purify the product.

Fatty ethanolamides have many uses such as; synthesis of sulfosuccinate surfactants, detergents, shampoos, lubricants and cosmetics due to their diversity of unique properties, economy and ease of preparation.[1] Fatty Ethanolamides are also found in the body. They represent a group of lipid mediators that play roles in lipid signaling within plants and animals.[2]Lauric acid (dodecanoic acid) is the main component found in coconut oil. It is a white powdery solid with a faint smell similar to soap or bay oil. It is a saturated carboxylic acid with a 12-carbon atom chain and can also be found in breast milk. Lauric acid can be used to make shampoo, soap, insecticides and cosmetics. Lauric acid can also be used to treat eczema, cold sores, the common flu, and preventing the transmission of HIV/AIDS from mothers to their babies. [3]

Mono-ethanolamine is also known as ethanolamine or 2-aminoethanol. It is usually abbreviated to ETA or MEA. Mono-ethanolamine is a colourless and viscous liquid with an odour which is similar to ammonia. Fatty acids are used to thin the blood, which prevents blood clots and can prevent heart attacks and strokes. They are used in the development of the nervous system and the brain. Mono-ethanolamine has a bifunctional nature, which allows it to exhibit the chemical properties of amines and alcohols. [4]

Method:The experiment was carried out in a fume cupboard at all times to prevent inhalation of the vapour given off during the experiment. A three necked round bottom flask was fitted to a plain column and a Liebig condenser and were held together by using a clamp. The flask was placed in an isomantle.

1. Firstly, 175g of lauric acid was placed in the flask and was heated to 140C.2. 56g (55cm3) of 2-aminoethanol was then slowly added from the funnel to the lauric acid.3. To start the reaction, the temperature was increased from 140C to 180C. As this was done, the temperature of the liquid shot up to 220C. The colour of the solution changed from colourless to a pale yellow then to a dark yellow. This indicated that the yield would not be accurate as a pale yellow colour was expected.4. The flask was left to cool to 180C, then maintained this temperature.5. Effervescence was observed and the apparatus was rearranged in order to collect the distillate.6. The reaction was stopped as soon as 12cm3 of distillate was collected in the graduated cylinder. The distillate consisted mostly of water and 5% of it was 2-aminoethanol, while the molten ethanolamide remained in the flask.7. The isomantle was removed and the mixture was left to cool down.8. Ice was collected in a container and was weighed using an electric scale. 9. In the fume cupboard, the cooled mixture was then poured into the container containing ice and the weight was taken again. 10. A small portion of the product was placed on a watch glass and left for the following week.11. A week later, the melting point was obtained. In order to do this, a capillary tube was cut in half and approximately 2-3mm of product was dabbed into the tube. The melting point was then obtained by using a melting point apparatus.

Figure 1- Isomantle[5] Figure 2- three neck flask[6] Figure 3- stand+clamp[7]Hazard and Risk Analysis

To minimise the risks of these chemicals; protective gloves, goggles and lab coats were worn throughout the experiment. The experiment was carried out in a fume cupboard, to again, minimise risks.

Lauric acid: [8]

Hazard and RisksPrecautions made to minimise risk

Irritant when in contact with skin1. Wear gloves and lab coats at all times, whilst in the lab.2. In case of contact with Lauric acid the person must remove any contaminated clothes. Skin must be washed with plenty of water for at least 15 minutes, and cover the irritated skin with an emollient (or disinfectant soap- only for more severe cases).3. Clothes must be washed thoroughly before reused.

Irritant when in contact with eyes1. Safety Goggles must be worn at all times, whilst in the lab.2. Immediately wash eyes for at least 15 minutes.3. Seek medical attention immediately.

Hazardous when inhaled1. Handle the acetic acid under a fume cupboard at all times this will prevent irritating and toxic fumes and gases, that are produced when acetic anhydride decomposes (Carbon monoxide and Carbon dioxide).2. Obtain medical advice immediately.3. The person must be evacuated from the area and enter an area with fresh air.

Harmful when ingested1. Loosen tight clothing.2. Do not encourage vomiting, unless directed so by a person with a medical profession.3. Obtain medical advice immediately.

Flammable1. Lauric acid may be combustible at high temperatures, so must stay well away from Ignition sources, combustible material, and excess heat.2. In case of fire use DRY chemical powder. For larger fires, water spray, fog or foam must be used.

2-aminoethanol:

Hazard and RisksPrecautions made to minimise risk

Irritant when in contact with skin- May cause irritation, redness, burns, and pain. May be absorbed through the skin.

1. Wear gloves and lab coats at all times, whilst in the lab.2. In case of contact, the person must remove any contaminated clothes. Skin must be washed with plenty of water for at least 15 minutes, and cover the irritated skin with an emollient (or disinfectant soap- only for more severe cases).3. Clothes must be washed thoroughly before reused.4. Seek medical attention immediately.

Irritant when in contact with eyes- Vapours and contact may cause severe irritation, burns, redness, pain, and blurred vision. Prolonged or repeated skin exposure may cause severe irritation or dermatitis.

1. Safety Goggles must be worn at all times, whilst in the lab.2. Immediately wash eyes for at least 15 minutes.3. Seek medical attention immediately.

Harmful when ingested- May cause mucosal burns of the mouth and oesophagus, abdominal pain, nausea, and vomiting. May cause systemic poisoning with symptoms paralleling inhalation.1. Loosen tight clothing.2. Do not encourage vomiting, unless directed so by a person with a medical profession.3. Obtain medical advice immediately.

Hazardous when inhaled- Vapour may cause irritation to the respiratory tract. Symptoms may include sore throat, coughing, respiratory distress, headache, lethargy, and narcosis. Exposure to higher concentrations may cause pulmonary irritation, and kidney and liver damage.

1. Handle the acetic acid under a fume cupboard at all times this will prevent irritating and toxic fumes and gases, that are produced when acetic anhydride decomposes (Carbon monoxide and Carbon dioxide).2. Obtain medical advice immediately.3. The person must be evacuated from the area and enter an area with fresh air.

Flammable1. May be combustible at high temperatures, so must stay well away from Ignition sources, combustible material and excess heat.2. In case of fire use water spray, dry chemical, alcohol foam, or carbon dioxide.

Results and Calculations:

ItemMass (g)

Mass of beaker and ice483.73

Mass of beaker and ice with molten ethanolamide699.23

Difference in mass215.50

Moles of 2-aminoethanol:Moles of lauric acid:(Mass/Molar mass)= (Mass/Molar mass)=56/61=175/200=0.9180.875

All products and reactants are in a 1:1 ratio.Limiting reagent was lauric acid as there were fewer moles.

Theoretical yield of lauric ethanolamide: g

Percentage yield of lauric ethanolamide: (215.5/212.63) 100= 101.35%

Required volume of distillate: 12cm3Theoretical mass of water: gPercentage yield of water: (12/15.75) 100= 76.19%

The melting point came in the range of 76-80C.

Discussions and Recommendations

The objectives of the experiment were to produce fatty ethanolamide by reacting lauric acid with 2-aminoethanol, as well as calculating the percentage yield of lauric ethanolamine and to determine the melting point of the desired product. The aim was achieved as the yield of fatty ethanolamide was calculated and the melting point was determined.

The greatest source of error during the experiment would have been from the temperature of the flask exceeding 180C. The reason why it may have exceeded that temperature may be because the lauric acid was added too quickly leading to a more exothermic reaction thus, increasing the temperature dramatically. Another error could have come from only collecting 10cm3 of distillate, while the required amount was 12cm3. As the required amount was not collected, this could have also contributed to getting a yield greater than 100%. The reason for removing the water was because it was a by-product and was not of interest. Could have also affected the purity of the fatty ethanolamide.

When rearranging the equipment, as the gloves were not heat proof it was a challenge and this caused a few drops of distillate to be lost. A non-digital thermometer was used to measure the temperature of the solution within the three necked rounded bottom flask. This meant that a human error was likely to occur as reading the thermometer to its exact decimal point was not possible.

The melting point observed was 76-80C, while compared to its average value it is 88-90C. This suggests that the product contained impurities, and the percentage yield obtained shows this too. In addition to this, a short range in values indicates a higher purity whereas the values that were determined had a large range. Unreacted lauric acid or water that had not been separated from the product could be one of those impurities.

Ways in which the experiment could have been improved would be; using a water bath instead of an isomantle, use gloves that are heat resistant which would make it easier to rearrange the apparatus halfway through the experiment and lastly, repeat the experiment three times.

NomenclatureVariableUnitSymbol

TemperatureDegrees CelsiusC

MassGramsg

VolumeCentimetres cubedcm3

References:1. Roila Awang; Cheong Kok Whye; Mahiran Basri; Rosnah Ismail; Razmah Ghazali and Salmiah Ahmad; Alkanolamide from 9,10-dihydroxystearic acid , Journal of Oil Palm Research Vol. 18 p. 231-238 June 2006.2. Kfalvi, A. (Editor) 2008. Cannabinoids and the brain. Springer.3. http://www.wisegeek.com/what-is-lauric-acid.htm4. http://www.studymode.com/essays/Fatty-Ethanolomides-1351847.html.5. http://www.geminibv.nl/labware/isopad-isomantle-mul-5l-mantelverwarming-en?set_language=en6. http://www.duran-group.com/en/products-solutions/laboratory-glassware/products/interchangeable-glassware/grinded-flask.html7. https://www.omni-inc.com/motor-stand-assemblies-motor-stand-for-omni-thglhthq-c-30_267_392_249.html8. http://www.sciencelab.com/msds.php?msdsId=9924459.