Question

1. Give ONE reagent which could be used instead of acetic anhydride.
2. Write a complete reaction mechanism for the synthesis of aspirin via the reaction
used in this experiment.

Answer 1

Answer:

1. Give ONE reagent which could be used instead of acetic anhydride

Acetyl chloride and acetic anhydride are often used instead of acetic acid because they are more reactive and give better yields of product.

2.Write a complete reaction mechanism for the synthesis of aspirin via the reactionused in this experiment

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. ... Since acetic acid is very soluble in water, it is easily separated from the aspirin product. The aspirin isolated in this step is the “crude product”.

Answer 2

Answer:

1.

• Salicylic acid and acetyl chloride react to form aspirin acetylsalicylic acid, however instead of acetic acid, hydrogen chloride gas is produced as a by-product which you would get from using acetic anhydride as the acetylating agent rather than acetyl chloride.

• Acetyl chloride and acetic anhydride are often used instead of acetic acid because they are more reactive and give better yields of product.

2.

• Aspirin is manufactured through an esterification process. When salicylic acid is treated with acetic anhydride, an acid derivative, the hydroxyl group of the acid is converted to an ester group $(R-OH R-OCOCH_{3} ).$