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What is the step-by-step mechanism for the synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide?

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The synthesis of ibuprofen from 2-methylpropylbenzene  isobutylbenzene  and carbon dioxide involves several steps. Here is a step-by-step mechanism for this process:1. Friedel-Crafts Alkylation:- In the first step, 2-methylpropylbenzene  isobutylbenzene  undergoes Friedel-Crafts alkylation with propionyl chloride  CH3CH2COCl  in the presence of an aluminum chloride  AlCl3  catalyst.- The AlCl3 activates the propionyl chloride by forming a complex with the carbonyl group, making the carbonyl carbon more electrophilic.- The activated propionyl chloride then reacts with the 2-methylpropylbenzene, attaching the propionyl group to the benzene ring via electrophilic aromatic substitution.2. Hydrolysis:- The ketone formed in the previous step is hydrolyzed to form a carboxylic acid. This is done by treating the ketone with a strong base, such as sodium hydroxide  NaOH , followed by acidification with a strong acid, such as hydrochloric acid  HCl .3. Kolbe-Schmitt Reaction:- The carboxylic acid is then converted to its corresponding sodium salt by treating it with sodium hydroxide  NaOH .- The sodium salt is then reacted with carbon dioxide  CO2  under high pressure and temperature  100-130C  to form the sodium salt of the desired ibuprofen.- This step is known as the Kolbe-Schmitt reaction, which involves the carboxylation of the aromatic ring at the ortho position relative to the carboxylic acid group.4. Acidification:- Finally, the sodium salt of ibuprofen is converted to the free acid form  ibuprofen  by treating it with a strong acid, such as hydrochloric acid  HCl .These steps provide a general overview of the synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide. There may be variations in the specific reagents and conditions used, but the overall process remains the same.
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