What is the main reaction in the synthesis of aspirin?
What is the main reaction in the synthesis of aspirin?
To prepare aspirin, salicylic acid is reacted with an excess of acetic anhydride. A small amount of a strong acid is used as a catalyst which speeds up the reaction. In this experiment, phosphoric acid will be used as the catalyst. The excess acetic acid will be quenched with the addition of water.
How aspirin is synthesized?
Aspirin is prepared by chemical synthesis from salicylic acid, through acetylation with acetic anhydride. The molecular weight of aspirin is 180.16g/mol. It is odourless, colourless to white crystals or crystalline powder.
What is the role of acetic anhydride in aspirin synthesis?
Acetic anhydride is the preferred acid derivative to synthesize aspirin commercially because the acetic acid produced in this reaction can be used again, by converting it back into acetic anhydride. When the reaction is complete, add 50 mL of cold water to the reaction mixture.
Why is the synthesized aspirin in the laboratory Cannot be used for commercial and pharmaceutical purposes?
In this laboratory activity you will synthesize aspirin, a derivative of salicylic acid. Salicylic acid and its derivatives are antipyretics. Salicylic acid itself is not used for these purposes because it has an irritating effect on the stomach. The most common salicylate used in medicine today is aspirin.
What are the byproducts of aspirin synthesis?
The byproduct of the synthesis of aspirin is acetic acid.
What functional groups are in aspirin?
There are three different functional groups in aspirin, which contribute to its properties, a weak acid soluble in basic solutions. These functional groups include carboxylic acid, ester, and an aromatic group.
How do you calculate the theoretical yield of aspirin synthesis?
Using the theoretical and actual you can calculate percent yield.
- Actual Yield of Aspirin in lab after filtered/dried (mock value) = 370 g.
- Mass of Theoretical Yield of Aspirin (mock value) = 360.3 g.
- Percent Yield = (Actual ÷ Theoretical) x 100 = (370 ÷ 360.3) x 100 = 103 %
How many grams of aspirin were obtained after the second synthesis?
1.081g of Salicylic acid was obtained after the first synthesis. It was thin, short white crystals and had a melting point range or 154-155 degrees Celsius. 1.600g of aspirin was obtained after the second synthesis. This was a white powder and had a melting point range of 134-135 degrees Celsius.
How do you make α-diketones?
α-Diketones are prepared either by the reaction of 2-lithio-1,3-dithianes with a nitrile oxide (Scheme 42) 248 or by the reaction of 2-lithiodithiolane with iron(pentacarbonyl) followed by alkylation with an alkyl halide. 249. Scheme 42.
What is the chemical name of aspirin made from?
Synthesis of Aspirin Aspirin is the single most manufactured drug in the world. Aspirin’s chemical name is acetylsalicylic acid, and it is synthesized from the reaction of acetic anhydride with salicylic acid in the presence of phos-phoric acid as a catalyst. The by-product is acetic acid (Figure 5.1).
Why is acetic acid used in the synthesis of aspirin?
Therefore during the synthesis of the aspirin some of the aspirin will be converted back to starting material. To help push the reaction toward the products, one could distill off the acetic acid. This is because the reduction of the products will cause more starting material to react to regain equilibrium.
