Compouds in the form of homodimeric, heterodimeric and/or homo and heteromultimeric pro-drugs; process for obtaining these pro-drugs and their acceptable pharmaceutical salts and use of compounds in the treatment of phosphodiesterasis-mediated deseases or dysfunction

Process for the obtainment of homodimeric, heterodimeric and/or homo and hetero multimeric pro-drugs, characterizing by comprehending the following phases:

• (a) Add to a reactor with stirring, cooling and heating systems, the monomeric unit and the solvent, under stirring within a temperature range from −10° C. to +100° C.;
• (b) Add the forming agent of the labile bond in its solid, liquid or gaseous states, diluted in solvents or directly in their natural states to the reaction medium, followed by a HCl capturing agent;
• (c) Keep the system under stirring following the intermediate compound formation, including the labile bridge, by means of chromatographic methods;
• (d) Add to reaction medium a defined amount of the second proper monomeric unit;
• (e) Keep the reaction medium obtained in (d) under stirring within a temperature range from −10° C. to +100° C., monitoring the formation of pro-drug by means of reliable analytic methods;
• (f) Obtain the pro-drug by means of suitable treatment of the reaction medium;
• (g) Purify the pro-drug by means of usual purification procedures, as, for instance, the recrystallization in suitable solvents.