2-Substituted pyrimidines of the formula I in which the index n and the substituents L, Ra, Rb, Rc, Rz, Ru, Rv, A′, A″ and A′″ are as defined in the description and: R1 is C3-C10-alkyl, C3-C10-alkenyl, C3-C10-alkynyl, C3-C12-cycloalkyl, C3-C10-cycloalkenyl or a five- to ten-membered saturated, partially unsaturated or aromatic heterocycle which is attached via carbon and contains one to four heteroatoms from the group consisting of O, N and S, R2 is halogen, cyano, C1-C4-alkyl, C2-C4-alkenyl, C2-C4-alkynyl, C1-C4-alkoxy, C3-C4-alkenyloxy or C3-C4-alkynyloxy, where the alkyl, alkenyl and alkynyl radicals of R2 may be substituted by halogen, cyano, nitro, C1-C2-alkoxy or C1-C4-alkoxycarbonyl, and R3 is cyano, CO2Ra, C(═O)NRzRb, C(═O)—N—ORb, C(═S)—NRaRb, C(═NORa)NRzRb, C(═NRa)NRzRb, C(═O)NRa—NRzRb, C(═N—NRzRc)NRaRb, C(═O)Ra, C(═NORb)Ra, C(═N—NRzRb)Ra, CRaRb—ORz, CRaRb—NRzRc, ON(═CRaRb), O—C(═O)Ra, NRaRb′, NRa(C(═O)Rb), NRa(C(═O)ORb), NRa(C(═O)—NRzRb), NRa(C(═NRc)Rb), NRa(N═CRcRb), NRa—NRzRb, NRz—ORa, NRa(C(═NRc)—NRzRb), NRa(C(═NORc)Rb), processes for preparing these compounds, compositions comprising these compounds and their pesticidal use are described.