Compounds of the formula I: ##STR00001## and N-oxides, salts, and stereoisomers thereof wherein A is OR.sup.1, NHS(.dbd.O).sub.pR.sup.2; wherein; R.sup.1 is hydrogen, C.sub.1-C.sub.6alkyl, C.sub.0-C.sub.3alkylenecarbocyclyl, C.sub.0-C.sub.3alkylene-heterocyclyl; R.sup.2 is C.sub.1-C.sub.6alkyl, C.sub.0-C.sub.3alkylenecarbocyclyl, C.sub.0-C.sub.3alkyleneheterocyclyl; p is independently 1 or 2; n is 3, 4, 5 or 6; denotes an optional double bond; L is N or CRz; Rz is H or forms a double bond with the asterisked carbon; Rq is H or when L is CRz, Rq can also be C.sub.1-C.sub.6alkyl; Rr is quinazolinyl, optionally substituted with one two or three substituents each independently selected from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6alkoxy, hydroxyl, halo, haloC.sub.1-C.sub.6alkyl, amino, mono- or dialkylamino, mono- or dialkylaminocarbonyl, C.sub.1-C.sub.6alkyl-carbonylamino, C.sub.0-C.sub.3alkylenecarbocyclyl and C.sub.0-C.sub.3 alkyleneheterocyclyl; R.sup.5 is hydrogen, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxyC.sub.1-C.sub.6alkyl or C.sub.3-C.sub.7cycloalkyl; R.sup.6 is hydrogen, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy, C.sub.0-C.sub.3alkylenecarbocyclyl, C.sub.0-C.sub.3alkylene-heterocyclyl, hydroxy, bromo, chloro or fluoro have utility in the treatment or prophylaxis of flaviviral infections such as HCV.