The synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide involves several steps. Here is a general outline of the mechanism:1. Friedel-Crafts Alkylation: The first step is the Friedel-Crafts alkylation of 2-methylpropylbenzene isobutylbenzene with propionyl chloride in the presence of a Lewis acid catalyst, such as aluminum chloride AlCl3 . This reaction forms a ketone, 2- 4-isobutylphenyl propanone.2. Hydrolysis: The ketone is then hydrolyzed in the presence of a strong base, such as sodium hydroxide NaOH , to form a carboxylic acid, 2- 4-isobutylphenyl propionic acid.3. Kolbe-Schmitt Reaction: The carboxylic acid is then reacted with carbon dioxide CO2 in the presence of a strong base, such as sodium hydroxide NaOH , under high pressure and temperature. This reaction, known as the Kolbe-Schmitt reaction, forms a sodium salt of the carboxylic acid, sodium 2- 4-isobutylphenyl propionate.4. Acidification: Finally, the sodium salt is acidified using a strong acid, such as hydrochloric acid HCl , to form ibuprofen, 2- 4-isobutylphenyl propionic acid.It is important to note that the synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide is not a direct reaction. The process involves multiple steps and intermediate compounds to achieve the final product.