The synthesis of ibuprofen from 2-methylpropylbenzene isobutylbenzene and carbon dioxide involves a few steps. The key step in this process is the carboxylation of isobutylbenzene to form 2- 4-isobutylphenyl propionic acid, which is then converted to ibuprofen through a series of reactions.The most suitable reaction conditions for the carboxylation step are as follows:1. Temperature: The reaction is typically carried out at a temperature between 150-200C. Higher temperatures can increase the reaction rate, but they may also lead to side reactions and decomposition of the reactants.2. Pressure: A high pressure of CO is required for the carboxylation reaction. The pressure should be in the range of 20-40 atm to ensure efficient conversion of isobutylbenzene to the desired product.3. Catalyst: A transition metal catalyst, such as palladium or nickel, is used to facilitate the carboxylation reaction. The catalyst is usually supported on a solid material like carbon or alumina. Additionally, a ligand like 1,3-bis diphenylphosphino propane dppp or 1,1'-bis diphenylphosphino ferrocene dppf can be used to improve the catalyst's performance.After the carboxylation step, the resulting 2- 4-isobutylphenyl propionic acid can be converted to ibuprofen through a series of reactions, including esterification, hydrolysis, and dehydration. These reactions can be carried out under relatively mild conditions, using common reagents and catalysts like sulfuric acid or p-toluenesulfonic acid.