0
How do salicylic acid and acetic anhydride react to form aspirin in a base mechanism?
Wiki User
∙ 14y ago
Salicylic acid + acetic anhydride react to form acetylsalicylic acid (aspirin) + acetic acid.
This reaction is performed in acidic conditions ( normally by adding sulfuric acid) and is heated.
Wiki User
∙ 15y ago
Wiki User
∙ 14y agoThe idea of creating aspirin in a basic medium is to create a better nucleophile. In this case, NaOH will deprotonate the phenol group of salicylic acid prior to its attack. Salicylic acid's carboxyl group does not participate in this reaction.
Sal-OH + -OH --> Sal-O- + H2O
A tetrahedral intermediate is formed when Sal-O- attacks the carbonyl group of acetyl anhydride. The double bond of the carbonyl group is broken, leaving a negative charge on its oxygen.
Sal-O- + CH3(C=O)O(C=O)CH3 --> (Sal-O-)--CH3COO(C=O)CH3
The double bond of the carbonyl group is reformed by resonance, which breaks the ester bond and creating -O(C=O)CH3 as the leaving group.
(Sal-O-)--CH3COO(C=O)CH3 --> (Sal-O-)--(C=O)CH3, which is aspirin
Add your answer:
Earn +20 pts
What percent salicylic acid in aspirin?
37.16% is the expected yield in the reaction of salicylic acid and acetic anhydride used to form aspirin.
What are the impurity in aspirin synthesis?
The main impurties are probably the unreacted reactants. i.e salicylic acid and some acetic anhydride (ethanoic anhydride)
What chemicals are needed to produce aspirin?
Salycylic acid and acetic anhydride with a sulphuric acid catalyst
How do you know which OH group on salicylic acid reacts to form aspirin?
Aspirin is formed in a reaction between salicylic acid and acetic anhydride. In this reaction it is the phenolic alcohol group that reacts to form the aspirin.
Mechanism of aspirin synthesis?
Aspirin is generally produced by the following mechanism (starting from basic materials) Phenol --(NaOH, CO2, heat)--> Sodium Salicylate (+para isomer) --(H2SO4)--> Salicylic acid --(acetic anhydride)--> acetylsalicylic acid (Aspirin) Due to the myriad of organic reactions, there are multiple possibilities at each stage. However, the above is the most efficient and common way of synthesizing Aspirin. For example, the last reaction (esterification) may be accomplished by using an acyl halide instead of an anhydride (e.g. ethanoyl/acetic chloride instead of acetic anhydride). However, the acyl halide is more costly to synthesize and more unstable to handle.
What is the process of making aspirin?
Aspirin is made when salicylic acid and acetic anhydride is reacted in the presence of an acid catalyst such as H2SO4. Acetylsalicylic acid (aspirin) and acetic acid is formed. The reaction is an esterification reaction.
What is the compound of aspirin?
The active medical ingredient in Aspirin is acetylsalicylic acid, or A.S.A.
What are the compound names for salicylic acid and acetic anhydride?
Your question has the names right in it. Maybe it's the chemical formulas you want. In that case, salicylic acid is C7H6O3 and acetic anhydride is C4H6O3.
How will you convert phenol into aspirin?
Aspirin (acetyl salycilic acid) is prepared from salycilic acid and acetic anhydride; salicylic acid is prepared from sodium phenoxide and carbon dioxide (Kolbe synthesis).
What is an alternative reagent to ethanoic anhydride in the synthesis of aspirin from salicylic acid?
Synthesis of acetyl chloride via the reaction of acetic acid with sulphuric acid
Aspirin is made by the reaction of salicylic acid with acetic an hydride what is the theoretical yield of aspirin if 85.0 grams of salicylic acid is treated with excess acetic an hydride?
Since salicylic acid is being reacted with excess acetic anhydride, salicylic acid is the limiting reactant of the reaction. The balanced equation of the reaction of salicylic acid and acetic anhydride indicates that their is a 1:1:1:1 ratio between every reactant and product. Based on this, it can be concluded that the moles of salicylic acid, if reacted entirely, will yield an equivalent amount of moles of aspirin. To find the theoretical yield, you must know the molecular weight of aspirin and salicylic acid. First, the amount of moles of salicylic acid must be calculated by dividing the gram amount of salicylic acid, which is 85 grams, and dividing it by its molecular weight, which is 138.12 grams per mole.85.0/138.12= 0.615 moles of salicylic acidThis is the mole amount of salicylic acid as well as the theoretical mole amount of aspirin. To convert the mole amount of aspirin into grams, this figure be multiplied by the molecular weight of aspirin, which is 180.15980.615 x 180.1598 = 111 grams of aspirin (when rounded to 3 significant figures)
In the preparation of aspirin water is added to the reaction flask Why?
The formation of aspirin will proceed faster if acetic anhydride is used in place of acetic acid. However, acetic anhydride will hydrolyze in the presence of water to form acetic acid, slowing down the reaction.
