It refers to a pharmacological synthesis, including a compound from pirrolidina-2, 5-diona, formula I,A. made of a mixture of I 'or both, where x is - nh-o-cq2 = cq3 -；Q2 and Q3 are independent h or C1-C6 asphalt； R1 and R2 are independent h, halogen, cyanogen, C1-C6 or alcox C1-C6, at least one carrier that can be accepted in pharmacology. It also refers to the racemic mixture of two compounds, such as 3 - (5-fluoro-1h-indoli-3-il) pirrolidin-2, 5-dioxin, etc. These compounds are inhibitors of 2,3-dihydroxy-1 enzyme (ido1) for the treatment or prevention of cancer and endocrine.Se refiere a una composicion farmaceutica que comprende un compuesto, derivado de pirrolidina-2,5-diona, de formula I´, de formula I´´ o una mezcla de ellos； en donde: X es -NH- o -CQ2=CQ3-； Q2 y Q3 son, independientemente, H o alquilo C1-C6； R1 y R2 son, independientemente, H, halo, ciano, alquilo C1-C6 o alcoxi C1-C6； y al menos un portador farmaceuticamente aceptable. Tambien se refiere a una mezcla racemica de ambos compuestos, siendo seleccionado 3-(5-fluoro-1H-indol-3-il)pirrolidin-2,5-diona, entre otros. Dichos compuestos son inhibidores de la enzima indolamina 2,3-dioxigenasa-1 (IDO1) siendo utiles en el tratamiento o prevencion de cancer y endometriosis
