A method for manufacturing 1,4-bis(4-phenoxybenzoyl)benzene, comprising: - 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, wherein the Lewis acid is chosen among the list consisting of: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, stannic chloride, titanium tetrachloride, and molybdenum pentachloride; wherein the Lewis acid is preferentially chosen among the list consisting of: aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride, and molybdenum pentachloride. - 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; 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, wherein the Lewis acid is chosen among the list consisting of: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, stannic chloride, titanium tetrachloride, and molybdenum pentachloride; wherein the Lewis acid is preferentially chosen among the list consisting of: aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride, and molybdenum pentachloride.