A method for manufacturing 1,4-bis(4-phenoxybenzoyl)benzene, including: providing a solvent, a Lewis acid, a first reactant and a second reactant, wherein the first reactant and the second reactant are respectively terephthaloyl chloride and diphenyl ether, or reversely; mixing the first reactant in the solvent to make a starting mixture; and, adding the second reactant to the starting mixture; wherein the Lewis acid is mixed, at least partly, to the starting mixture before adding the second reactant to the starting mixture, and/or wherein the Lewis acid is mixed, at least partly, with the second reactant and added together to the starting mixture, and wherein the temperature of the starting mixture is greater than 5° C. during at least part of the step of adding the second reactant to the starting mixture; so as to obtain a product mixture comprising a 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex.