Use to control Weeds, particularly in crops of useful plants.Claim 1: a compound of formula (1) or one of its Salts agronomically acceptable, where X is o or s； a u00b9 is CH or N； n or a-squared is cr u00b3； A u00b3 is n or cr u2074； a u2074 is n or cr u2075； a u2075 is n or CH, where r u00b9 is selected from the group consisting of c u2081 u208b u2086 haloalquilo c u2081 u208b u2086 (alkyl, and the Coxi c u2081 u208b u2086) - (alkyl c u2081 u208b u2083)； R u00b2 is selected from the group consisting of hydrogen, alkyl c u2081 u208b u2086, haloalquilo c u2081 u208b u2086,(c u2081 u208b u2083 alkoxy) - (alkyl c u2081 u208b u2083), (haloalcoxi c u2081 u208b u2083) - (alkyl, alkoxy c u2081 u208b u2083) c u2081 u208b u2083 (alkoxy) - c u2081 u208b u2083) - (alkyl c u2081 u208b u2083), (c u2081 u208b u2083 (alkoxy) - haloalquilo c u2081 u208b u2083), (c u2081 u208b u2083 (alkoxy) - c u2081 u208b u2083 (alkoxy) - haloalquilo c u2081 u208b u2083), (cicloalcoxi oxasustituido c u2084 u208b u2086 - (alkyl) c u2081 u208b u2083), (cicloalquil oxasustituido c u2084 u208b u2086 (alkoxy) - c u2081 u208b u2083) - (alkyl c u2081 u208b u2083), (cicloalcoxi oxasustituido c u2084 u208b u2086) - (haloalquilo c u2081 u208b u2083)(cicloalquil oxasustituido c u2084 u208b u2086 (alkoxy) - c u2081 u208b u2083) - (haloalquilo c u2081 u208b u2083), (alcanosulfonil c u2081 u208b u2083) - (alquilamino c u2081 u208b u2083) (alkyl) - c u2081 u208b u2083), (alcanosulfonil c u2081 u208b u2083) - (cicloalquilamino c u2083 u208b u2084) (alkyl) - c u2081 u208b u2083), (alquilcarbonil c u2081 u208b u2086) - (alkyl c u2081 u208b u2083 (CICL) Oalquil c u2083 u208b u2086) - (alquenilo c u2082 u208b u2086), alquinilo c u2082 u208b u2086, alquenilo c u2082 u208b u2086, haloalquenilo c u2082 u208b u2086 (alkyl, cyano -, c u2081 u208b u2086)Arilcarbonil - (alkyl (aryl c u2081 u208b u2083) which can be optionally substituted by one or more substituents of the Group comprising Halogen, alkoxy alkyl c u2081 u208
