This invention concerns the use of compounds of formula the N-oxides, the pharmaceutically acceptable addition salts, quaternary amines and the stereochemically isomeric forms thereof, wherein -a1=a2-a3=a4- forms a phenyl, pyridinyl, pyrimidinyl, pyridazinyl or pyrazinyl with the attached vinyl group; n is 0 to 4; and where possible 5; R1 is hydrogen, aryl, formyl, C1-6alkylcarbonyl, C1-6alkyl, C1-6alkyloxycarbonyl, substituted C1-6alkyl, or substituted C1-6alkyloxyC1-6alkylcarbonyl; each R2 independently is hydroxy, halo, optionally substituted C1-6alkyl, C2-6alkenyl or C2-6alkynyl, C3-7cycloalkyl, C1-6alkyloxy, C1-6alkyloxycarbonyl, carboxyl, cyano, nitro, amino, mono- or di(C1-6alkyl)amino, polyhalomethyl, polyhalomethyloxy, polyhalomethylthio, —S(═O)pR6, —NH—S(═O)pR6, —C(═O)R6, —NHC(═O)H, —C(═O)NHNH2, —NHC(═O)R6, —C(═NH)R6 or a 5-membered heterocyclic ring; p is 1 or 2; L is optionally substituted C1-10alkyl, C2-10alkenyl, C2-10alkynyl or C3-7cycloalkyl; or L is —X—R3 wherein R3 is optionally substituted phenyl, pyridinyl, pyrimidinyl, pyrazinyl or pyridazinyl; X is —NR1—, —NH—NH—, —N═N—, —O—, —C(═O)—, —CHOH—, —S—, —S(═O)— or —S(═O)2—; Q is hydrogen, C1-6alkyl, halo, polyhalo-C1-6alkyl or an optionally substituted amino group; Y represents hydroxy, halo, C3-7cycloalkyl, optionally substituted C1-6alkyl, C2-6alkenyl or C2-6alkynyl, C1-6alkyloxy, C1-6alkyloxycarbonyl, carboxyl, cyano, nitro, amino, mono- or di(C1-6alkyl)amino, polyhalomethyl, polyhalomethyloxy, polyhalomethylthio, —S(═O)pR6, —NH—S(═O)pR6, —C(═O)R6, —NHC(═O)H, —C(═O)NHNH2, —NHC(═O)R6, —C(═NH)R6 or aryl; aryl is optionally substituted phenyl; Het is an optionally substituted heterocyclic radical; for the manufacture of a medicine for the treatment of subjects suffering from HIV (Human Immunodeficiency Virus) infection.