Process for the preparation of Lapatinib of formula or a salt thereof: comprising the following steps: (a) Deprotection reaction of the compound 2-(methylsulphonyl)- N - ({5-[4-(tetrahydro-2 H -piran-2-yloxy)quinazolin-6-yl]furan-2-yl}methyl)ethanamine of formula: to give the compound 6-[5-({[2-(methylsulphonyl)ethyl]amino}methyl)furan- 2-yl] quinazolin-4-ole of formula or a salt thereof: (b) Amine protection reaction of the intermediate of formula to give the N-protected-6-[5-({[2-(methylsulphonyl)ethyl] amino}methyl)furan-2-yl] quinazolin-4-ole of formula: wherein R is CF 3; (c) Conversion of the intermediate of formula to give the N-protected-N-{[5-(4-substituted-quinazolin-6-yl)furan-2-yl]methyl}-2-(methylsulphonyl)ethanamine of formula: wherein R has the same meaning as described in step (b) and X is chosen in the group consisting of Fluorine, Chlorine, Bromine, Iodine, O-Ms (mesylate), O-Ts (tosylate), O-Tf (triflate), ethanesulfonate (esylate), benzenesulfonate (besylate), p-bromobenzenesulfonate (brosylate), p-nitrobenzenesulfonate (nosylate); (d) Reaction of the intermediate of formula with 3-chloro-4-[(3-fluorobenzyl)oxy]aniline of formula: to give the N-protected Lapatinib of formula: wherein R has the same meaning as described in step (b); (e) Deprotection reaction of N-protected Lapatinib of formula to give Lapatinib of formula or salts thereof; or, process wherein steps (a) and (b) are respectively substituted by the following steps: (a-bis) Amine protection reaction of the intermediate of formula to give the N-protected-2-(methylsulphonyl)- N -({5-[4-(tetrahydro-2 H -piran-2-yloxy) quinazolin-6-yl] furan-2-yl}methyl)ethanamine of formula (III-bis): wherein R has the same meaning as described in step (b); (b-bis) Deprotection reaction of the intermediate of formula (III-bis) to give the N-protected-6-[5-({[2-(methylsulponyl)ethyl]amino}methyl)furan-2-yl] quinazolin-4-ole of formula: wherein R has the same meaning as described in step (b). (a) Deprotection reaction of the compound 2-(methylsulphonyl)- N - ({5-[4-(tetrahydro-2 H -piran-2-yloxy)quinazolin-6-yl]furan-2-yl}methyl)ethanamine of formula: to give the compound 6-[5-({[2-(methylsulphonyl)ethyl]amino}methyl)furan- 2-yl] quinazolin-4-ole of formula or a salt thereof: (b) Amine protection reaction of the intermediate of formula to give the N-protected-6-[5-({[2-(methylsulphonyl)ethyl] amino}methyl)furan-2-yl] quinazolin-4-ole of formula: wherein R is CF 3; (c) Conversion of the intermediate of formula to give the N-protected-N-{[5-(4-substituted-quinazolin-6-yl)furan-2-yl]methyl}-2-(methylsulphonyl)ethanamine of formula: wherein R has the same meaning as described in step (b) and X is chosen in the group consisting of Fluorine, Chlorine, Bromine, Iodine, O-Ms (mesylate), O-Ts (tosylate), O-Tf (triflate), ethanesulfonate (esylate), benzenesulfonate (besylate), p-bromobenzenesulfonate (brosylate), p-nitrobenzenesulfonate (nosylate); (d) Reaction of the intermediate of formula with 3-chloro-4-[(3-fluorobenzyl)oxy]aniline of formula: to give the N-protected Lapatinib of formula: wherein R has the same meaning as described in step (b); (e) Deprotection reaction of N-protected Lapatinib of formula to give Lapatinib of formula or salts thereof; (a-bis) Amine protection reaction of the intermediate of formula to give the N-protected-2-(methylsulphonyl)- N -({5-[4-(tetrahydro-2 H -piran-2-yloxy) quinazolin-6-yl] furan-2-yl}methyl)ethanamine of formula (III-bis): wherein R has the same meaning as described in step (b); (b-bis) Deprotection reaction of the intermediate of formula (III-bis) to give the N-protected-6-[5-({[2-(methylsulponyl)ethyl]amino}methyl)furan-2-yl] quinazolin-4-ole of formula: wherein R has the same meaning as described in step (b).