The present invention relates to a novel and improved process for the preparation of the compound 2-{4-[2-({[2-(4-chlorophenyl)-1,3-thiazol-4-yl]methyl}sulfanyl) -3,5-dicyano-6-(pyrrolidin-1-yl)-pyridin-4-yl]-phenoxy}-ethyl-L- alanyl-L-alaninate monohydrochloride of formula (I), new precursors for their preparation, as well as to the production and use of the crystalline modification I of 2-{4-[2-({[2-(4-chlorophenyl)-1,3-thiazol-4-yl]methyl}sulfanyl) -3,5-dicyano-6-(pyrrolidin-1-yl)pyridin-4-yl]phenoxy}ethyl-L-ala nyl-L-alaninate monohydrochloride of formula (I).La presente solicitud se refiere a un procedimiento nuevo y mejorado para la preparación del compuesto 2-{4[2-({[2-(4-clorofen il)-1,3-tiazol-4-il]metil}sulfanil)-3,5-diciano-6-(pirrolidin-1-i l)piridina-4-il]fenoxi}etil-L-alanil-L-alaninato-monohidrocloruro de la fórmula (I), (ver Fórmula) nuevas fases previas para su preparación y la preparación y uso de la modificación cristalina I de 2-{4-[2-({[2-(4-clorofenil)-1,3-tiazol-4-il]metil}sulfanil)-3 ,5-diciano-6-(pirrolidin-1-il)piridina-4-il]fenoxi}etil-L-alanil- L-alaninato-monohidrocloruro de la fórmula (I).
