Claim 1: A substituted pyrimidine compound as a quinurenine-3-mono-oxygenase inhibitor, characterized in that it is selected from the compounds of the formula (1) and their pharmaceutically acceptable salts and prodrugs, wherein: R¹ is selected from optionally substituted aryl and optionally substituted heteroaryl； R² is selected from cyano, optionally substituted heteroaryl and optionally substituted heterocycloalkyl； R³ is selected from hydrogen and optionally substituted lower alkyl； and R⁴ is selected from hydrogen, halo, optionally substituted lower alkyl, hydroxyl, optionally substituted lower alkoxy, and optionally substituted amino,O R1 and r830808,With the atoms added to the formula, a double ring equation ring (2) is formed. The alternative formula ring is m = 0 or 1, n = 0 or 1, provided that at least one of M and N is 1, provided that: (1) when R2 is 4-methyleneoxazol-2-ilo, R3 is methyl, r8308es is hydrogen, so R1 is 3, (2) If R 3 and r83088 are hydrogen, R1 is not 5-chloropyridine-3-ilo, 3.5-dichlorophenyl, or the rest of the formula (3), wherein R2 is halogen, R2 is hydrogen, halo, trifluorometoxi, methyl, or isopropyl.Reivindicación 1: Un compuesto de pirimidina sustituida como inhibidor de quinurenina-3-monooxigenasa, caracterizado porque se selecciona de los compuestos de la fórmula (1) y sus sales y profármacos farmacéuticamente aceptables, en la que: R¹ se selecciona de arilo opcionalmente sustituido y heteroarilo opcionalmente sustituido； R² se selecciona de ciano, heteroarilo opcionalmente sustituido y heterocicloalquilo opcionalmente sustituido； R³ se selecciona de hidrógeno y alquilo inferior opcionalmente sustituido； y R⁴ se selecciona de hidrógeno, halo, alquilo inferior opcionalmente sustituido, hidroxilo, alcoxi inferior opcionalmente sustituido, y amino opcionalmente sustituido, o R¹ y R⁴, tomados junto con los átomos a los que se unen forman un anillo bicíclico de la fórmula (2) que está opcionalmente sustituido en el que m es 0 ó 1 y n
