The present invention concerns compounds of formula (A₁)(A₂)N—R¹ (I),the N-oxide forms, the pharmaceutically acceptable addition salts, the quaternary amines and stereochemically isomeric forms thereof, wherein R¹ is substituted C_1-6alkyl; —S(O)—R⁸; —S(O)₂—R⁸; C_7-12alkylcarbonyl; optionally substituted C_1-6alkyloxycarbonylC_1-6alkylcarbonyl; with R⁸ being C_1-6alkyl, aryl¹ or Het¹; (A₁)(A₂)N— is the covalently bonded form of the corresponding intermediate of formula (A₁)(A₂)N—H, which is a HIV replication inhibiting pyrimidine of formula ##STR1##