Abstract Acetic Anhydride and p-Aminophenol were heated in a vial attached to an air condenser to synthesize crude acetaminophen, resulting in 0.097 grams (47.48% yield). The crude acetaminophen was then recrystallized in a solvent of water and methanol over heat resulting in 0.082 grams (39.61% yield) of pure acetaminophen. Melting points of both crude and pure acetaminophen were taken, and found to be 165.9 - 170.9°C and 168.2 - 171.5°C, respectively. The literature melting point of acetaminophen is 169.5 – 171.0°C, indicating that our final product was pure.
Introduction The synthesis of acetaminophen involves the attraction of the electrophilic carbonyl group of acetic anhydride to the nucleophilic NH2
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An automatic pipet was used to measure 0.450 mL water and 0.165 mL acetic anhydride and was added to the conical vial. A spin vane was placed into the vial and an air condenser was attached.
Heating:
The mixture was heated at 120°C using an aluminum block and was stirred gently. After all of the solid dissolved, it was heated for 20 additional minutes to ensure the reaction was complete.
Isolation of Crude Acetaminophen: The vial was removed from the heat and cooled to room temperature. The spin vane was rinsed with 2-3 drops of warm water over the conical vial. The vial was cooled to room temperature then placed in an ice bath for 15 minutes. The liquid was decanted from the mixture and the resulting crystals were dried on filter paper. The crystals were then placed on a watch glass for further drying. The crystals were weighed and a small sample was placed into a capillary tube for melting point determination.
Crystallization of Acetaminophen: The product was placed in a Craig tube and several drops of hot (100°C) solvent (50% water, 50% methanol, by volume) was added and heated until all of the crystals dissolved. The Craig tube was plugged and set in an Erlenmeyer flask to cool. Crystallization was induced once the mixture was at room temperature by scratching the inner wall of the tube. It was then placed into an ice bath for ten minutes until crystallization was complete. The tube was then
The product was then suspended in 2 ml of water with a stir rod in a 50 ml Erlenmeyer flask and heated to boiling. Water was added in one milliliter increments until all the product was dissolved (18 ml added total). The saturated solution was allowed to slowly cool, and gradual white crystal formation was observed. Recrystallized product was collected once more by suction filtration with the Hirsch funnel once crystallization ceased. Collected product dried on a watch glass for a week, weighed 0.14 g (1.2 mmol), and the melting point was 139°-141°
In experiment two, 1.48g of the unknown solid was recovered. From this mass, it was determined approximately 30mL of boiling water was needed for crystallization of acetanilide and about 121mL for phenacetin. Phenacetin would require more solvent because it is less
The wet, crude product was placed into the 50 mL Erlenmeyer flask. Small amounts of CaCl2 were added to dry the solution. The flask was sealed and the mixture was swirled and left to settle. Once
21) After all of the solid dissolves, move the flask from the hot plate and allow it cool to room temperature. After a while, crystals should appear in the flask.
The solution that was performed in this experiment was to use sulfuric acid in order to form a protonated alcohol, so when the halogen or nucleophile back attacks the compound, water is displaced. Once the alcohol is protonated, the solution reacts in either an SN1 or SN2 mechanism.
The week after, a recrystallization was performed on the previous week’s crude product. The product ethereal solution was first heated on a steam bath until dry. During the heating, a beaker of methanol was collected and also placed on the steam bath. Once the product was dry, it was cooled to room temperature and then placed in an ice-water bath. The now boiling methanol was added to the crude crystals and a recrystallization was performed. Once completed, the now purified product was collected via Buchner vacuum filtration and stored in drawer to dry for a week. Afterwards, a melting point range of the purified product was obtained by using a Mel-temp apparatus. Lastly, an
Benzyltriphenylphosphonium chloride (0.201g) and 9-anthraldehyde (0.116g) were weighed and added to a short-neck round-bottomed flask (5ml). Dichloromethane (2ml) was measured using a measuring cylinder and added to the
In this preparative lab, an aldol (trans-p-anisalacetophenone) was produced from the reaction between p-anisaldehyde and acetophenone with the presence sodium hydroxide. The reaction also showed the importance of an enolate and the role it played in the mechanism. Sodium hydroxide acts as a catalyst in this experiment and is chosen because of its basic conditions and pH. The acetophenone carries an alpha hydrogen that has a pKa between 18 and 20. This alpha hydrogen is acidic because of its location near the carbonyl on acetophenone. When the sodium hydroxide is added, it deprotonates the hydrogen and creates an enolate ion. This deprotonation creates a nucleophilic carbon that can attack an electrophilic carbon (like a parent
The objective of this lab is to synthesize acetaminophen from p-aminophenol. The techniques used to do so, consist of: reflux with heat to allow reaction to occur at a reasonable time period, extraction and filtration to isolate the desired product, and characterization of the product by analyzing IR spectras and melting points. Acetaminophen considered synthesized, primarily due to the IR spectrum exhibiting all the bond vibrations is the amide group. The percent yield of 124.6% imply that there was a mechanical error that occurred, thus, also tampering with the progression of the chemical reaction. The wide melting point range of 165 C-169 C denote the impurity of the acetaminophen product.
The purpose of this lab was to synthesize aspirin, determine the theoretical yield, compare the percent yield to the theoretical yield and test the purity of aspirin by adding Iron (III) chloride to the product.
Crystals were collected in a Buchner funnel, washed with alcohol, then ether, then transferred into a sample tube for storage.
An Erlenmeyer flask was used to accommodate the largest volume of recrystallization solvent calculated and was cooled in an ice bath to increase the yield of crystals. The solid was collected by vacuum filtration and washed with a small amount of ice water. The product is then dried to a constant mass by use of an oven and weighed. A small amount of the unknown was compared to two samples of acetanilide and phenacetin for a melting point range to determine the identity. The temperature of the unknown was recorded when the first trace of liquid can be seen and when the unknown was completely liquid.
This report presents the synthesis of Aspirin (acetylsalicylic acid), as the product of the reaction of salicylic acid with ethanoic anhydride under acidic conditions. Aspirin was purified through recrystallisation by vacuum filtration, followed by desiccation of the Aspirin crystal over silica gel. The percentage yield was calculated as 44.89% and a sample of Aspirin was analysed using infra-red spectroscopy and compared to the spectrum of pure Aspirin, this served as an introduction to the identification of functional groups in organic compounds. The melting point was calculated using an IA9000M apparatus and recorded to be 35.2°C, which was slightly below the melting point of pure Aspirin; known to be between 138-140°C. Both IR spectroscopy and melting point measurement were used verify the purity of synthetic Aspirin made, which proved to be fairly pure under these laboratory conditions.
Tube 4 now should only have crude solid in the tube and it is then weighed. The tube is placed into a 50℃ water bath and then approximately 0.5 -1 ml of methanol is added, as well as H2O until the solution gets cloudy, once the solution is dissolved it is cooled to room temperature and then iced. The crystals are then collected using a Hirsh funnel. Next a small amount (~ 0.1g) of the crystals are placed into a melting point tube and placed into the melting point machine to record the unknown neutral substances melting point.
In conclusion, the aim; to synthesis Acetaminophen (Panadol) and calculate its purity was achieved as there was a moderate percentage yield of 64.07% which allowed for the