A method of hydrodefluorination of aromatic trifluoromethyl compounds of formula I wherein A, B, X, G and Z are independently selected from the group comprising H, I, Br, F, Cl, CF 3, COOR, NO 2, N=N-R, SO 3 R, CH 2 R, OR, NR 2, CH 2 NR 2, R-C=O, CN; wherein R is H, C 1 -C 8 alkyl, C 6 -C 14 aryl, or C 2 -C 10 heterocyclyl containing one to four heteroatoms independently selected from O, S, N; in alkaline aqueous environment, said method comprising the steps of: a) adding to an aqueous or colloid solution of the compound of formula I, at temperature within the range of 0 to 100 °C a mixture comprising: - component A, which is an alloy containing aluminium (Al) acting as reducing agent and nickel (Ni) acting as hydrodefluoration catalyst, wherein the molar ratio of CF 3: Al is within the range of 1 mol of CF 3 to 10 or more mol Al, and the molar ratio of CF 3: Ni is within the range of 1 mol CF 3 to 4.6 or more mol Ni; - component B, which is at least one alkali metal hydroxide or carbonate in molar ratio to Al 2:1 to 6:1, wherein the amount used corresponds to pH of the reaction mixture higher than 11; b) stirring the resulting reaction mixture at a temperature within the range of 10 to 100 °C, for at least 60 minutes and at most 24 hours; c) separating the nickel sludge from the aqueous phase of the reaction mixture; d) adjusting pH of the separated aqueous phase of the reaction mixture to a value within the range of 6 to 9, which causes precipitation of insoluble aluminium salts which adsorb microparticles of nickel and organic compounds from the mixture, and separating the precipitate. wherein A, B, X, G and Z are independently selected from the group comprising H, I, Br, F, Cl, CF 3, COOR, NO 2, N=N-R, SO 3 R, CH 2 R, OR, NR 2, CH 2 NR 2, R-C=O, CN; wherein R is H, C 1 -C 8 alkyl, C 6 -C 14 aryl, or C 2 -C 10 heterocyclyl containing one to four heteroatoms independently selected from O, S, N; in alkaline aqueous environment, said method comprising the steps of: a) adding to an aqueous or colloid solution of the compound of formula I, at temperature within the range of 0 to 100 °C a mixture comprising: - component A, which is an alloy containing aluminium (Al) acting as reducing agent and nickel (Ni) acting as hydrodefluoration catalyst, wherein the molar ratio of CF 3: Al is within the range of 1 mol of CF 3 to 10 or more mol Al, and the molar ratio of CF 3: Ni is within the range of 1 mol CF 3 to 4.6 or more mol Ni; - component B, which is at least one alkali metal hydroxide or carbonate in molar ratio to Al 2:1 to 6:1, wherein the amount used corresponds to pH of the reaction mixture higher than 11; b) stirring the resulting reaction mixture at a temperature within the range of 10 to 100 °C, for at least 60 minutes and at most 24 hours; c) separating the nickel sludge from the aqueous phase of the reaction mixture; d) adjusting pH of the separated aqueous phase of the reaction mixture to a value within the range of 6 to 9, which causes precipitation of insoluble aluminium salts which adsorb microparticles of nickel and organic compounds from the mixture, and separating the precipitate. a) adding to an aqueous or colloid solution of the compound of formula I, at temperature within the range of 0 to 100 °C a mixture comprising: - component A, which is an alloy containing aluminium (Al) acting as reducing agent and nickel (Ni) acting as hydrodefluoration catalyst, wherein the molar ratio of CF 3: Al is within the range of 1 mol of CF 3 to 10 or more mol Al, and the molar ratio of CF 3: Ni is within the range of 1 mol CF 3 to 4.6 or more mol Ni; - component B, which is at least one alkali metal hydroxide or carbonate in molar ratio to Al 2:1 to 6:1, wherein the amount used corresponds to pH of the reaction mixture higher than 11; - component A, which is an alloy containing aluminium (Al) acting as reducing agent and nickel (Ni) acting as hydrodefluoration catalyst, wherein the molar ratio of CF 3: Al is within the range of 1 mol of CF 3 to 10 or more mol Al, and the molar ratio of CF 3: Ni is within the range of 1 mol CF 3 to 4.6 or more mol Ni; - component B, which is at least one alkali metal hydroxide or carbonate in molar ratio to Al 2:1 to 6:1, wherein the amount used corresponds to pH of the reaction mixture higher than 11; b) stirring the resulting reaction mixture at a temperature within the range of 10 to 100 °C, for at least 60 minutes and at most 24 hours; c) separating the nickel sludge from the aqueous phase of the reaction mixture; d) adjusting pH of the separated aqueous phase of the reaction mixture to a value within the range of 6 to 9, which causes precipitation of insoluble aluminium salts which adsorb microparticles of nickel and organic compounds from the mixture, and separating the precipitate.