The synthesis of ibuprofen from 2-methylpropylbenzene and carbon dioxide can be achieved through a two-step process: carboxylation and Friedel-Crafts acylation. A cobalt catalyst and an organocatalyst can be used to facilitate the carboxylation step.1. Carboxylation:In this step, 2-methylpropylbenzene is converted to 2-methylpropylbenzoic acid using carbon dioxide. The reaction conditions for this step are as follows:- Catalyst: A combination of a cobalt catalyst such as CoBr2 and an organocatalyst such as N-heterocyclic carbene or NHC is used.- Temperature: The reaction is typically carried out at a temperature of 100-150C.- Pressure: Elevated CO2 pressure around 30-50 bar is required to facilitate the carboxylation reaction.- Solvent: A polar aprotic solvent, such as dimethylformamide DMF or dimethyl sulfoxide DMSO , is used to dissolve the reactants and catalysts.2. Friedel-Crafts Acylation:In this step, 2-methylpropylbenzoic acid is converted to ibuprofen through Friedel-Crafts acylation with isobutyl chloroformate. The reaction conditions for this step are as follows:- Catalyst: A Lewis acid catalyst, such as aluminum chloride AlCl3 or boron trifluoride BF3 , is used.- Temperature: The reaction is typically carried out at a temperature of 0-25C.- Solvent: A non-polar solvent, such as dichloromethane DCM or chloroform, is used to dissolve the reactants and catalysts.To optimize the yield and purity of the final product, the following strategies can be employed:1. Use of excess CO2 in the carboxylation step to drive the reaction to completion.2. Careful control of temperature and pressure during the carboxylation step to avoid side reactions and decomposition of the catalysts.3. Use of anhydrous reaction conditions and freshly dried catalysts to prevent hydrolysis of the acid chloride intermediate in the Friedel-Crafts acylation step.4. Purification of the final product through recrystallization or column chromatography to remove any impurities and unreacted starting materials.