A method for manufacturing an electronic tag to be affixed onto a product includes providing, in an electrically conductive film of a foil for packaging, packing or transporting the product, areas devoid of any electrically conductive material for delimiting in the electrically conductive film at least one antenna pattern for forming an antenna for an RFID tag. The invention also relates to the compounds of formula: a process for their preparation and the pharmaceutical compositions containing them. Pharmaceutical compositions and methods of treatment are also included.