The synthesis of ibuprofen from 2-methylpropylbenzene isobutylbenzene and carbon dioxide involves several steps. The overall process is known as the "Boots Process," which was developed by the Boots Company in the 1960s. Here is the step-by-step mechanism:1. Friedel-Crafts Alkylation: The first step is the alkylation of the benzene ring. Isobutylbenzene reacts with propionyl chloride in the presence of anhydrous aluminum chloride AlCl3 as a Lewis acid catalyst. This Friedel-Crafts acylation reaction forms 2- 4-isobutylphenyl propanoyl chloride.2. Hydrolysis: The acyl chloride formed in the previous step is then hydrolyzed in the presence of water and a base, such as sodium hydroxide NaOH , to form 2- 4-isobutylphenyl propionic acid, which is an intermediate compound.3. Kolbe-Schmitt Reaction: The intermediate compound undergoes a carboxylation reaction with carbon dioxide CO2 in the presence of a base, typically sodium or potassium hydroxide, under high temperature and pressure. This reaction is known as the Kolbe-Schmitt reaction, and it results in the formation of the sodium salt of ibuprofen.4. Acidification: Finally, the sodium salt of ibuprofen is treated with a strong acid, such as hydrochloric acid HCl , to obtain the final product, ibuprofen, in its free acid form.In summary, the synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide involves Friedel-Crafts alkylation, hydrolysis, Kolbe-Schmitt reaction, and acidification steps.