0 votes
26 views
in Chemical synthesis by (138k points)
What is the mechanism of the reaction used in the synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide, and what are the key conditions and catalysts required for this transformation?

1 Answer

0 votes
by (138k points)
The synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide involves a series of reactions. The overall process can be divided into three main steps:1. Friedel-Crafts acylation of 2-methylpropylbenzene2. Hydrolysis of the acylated product3. Carboxylation of the hydrolyzed productHere is a detailed description of the mechanism and the key conditions and catalysts required for each step:1. Friedel-Crafts acylation of 2-methylpropylbenzene:In this step, 2-methylpropylbenzene reacts with acetyl chloride in the presence of a Lewis acid catalyst, such as aluminum chloride  AlCl3 , to form an acylated product. The mechanism involves the formation of an acylium ion from the reaction of acetyl chloride with the Lewis acid catalyst. The acylium ion then reacts with the aromatic ring of 2-methylpropylbenzene through electrophilic aromatic substitution, resulting in the formation of the acylated product.Key conditions and catalysts:- Acetyl chloride as the acylating agent- Aluminum chloride  AlCl3  as the Lewis acid catalyst- Anhydrous conditions to prevent the formation of unwanted side products2. Hydrolysis of the acylated product:The acylated product from the previous step is then hydrolyzed to form a carboxylic acid. This is typically done using aqueous hydrochloric acid  HCl  or sulfuric acid  H2SO4  as the acid catalyst. The mechanism involves the nucleophilic attack of water on the carbonyl carbon of the acylated product, followed by proton transfer and elimination of the leaving group to form the carboxylic acid.Key conditions and catalysts:- Aqueous hydrochloric acid  HCl  or sulfuric acid  H2SO4  as the acid catalyst- Heating to facilitate the hydrolysis reaction3. Carboxylation of the hydrolyzed product:The carboxylic acid formed in the previous step is then reacted with carbon dioxide to form ibuprofen. This reaction is typically carried out under high pressure and temperature in the presence of a transition metal catalyst, such as palladium  Pd  or nickel  Ni , and a base, such as potassium carbonate  K2CO3 . The mechanism involves the formation of a metal-carboxylate complex, followed by the insertion of carbon dioxide into the metal-carbon bond, and finally, the reductive elimination to form the final ibuprofen product.Key conditions and catalysts:- Carbon dioxide as the carboxylating agent- Transition metal catalyst, such as palladium  Pd  or nickel  Ni - Base, such as potassium carbonate  K2CO3 - High pressure and temperature to facilitate the carboxylation reaction
Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...