A compound of the formula I: ##STR00001## wherein: X is CH or N; Y is O
or S; Z is OH, NH.sub.2, NMeR.sup.3, NHR.sup.3; OR.sup.3 or 5- or
6-membered heterocycle, having 1 to 4 heteroatoms selected from O, N and
S, said heterocycle being optionally substituted with from 1 to 4
substituents; A is N, COR.sup.7 or CR.sup.5, wherein R.sup.5 is H,
halogen, or (C.sub.1-6) alkyl and R.sup.7 is H or (C.sub.1-6 alkyl), with
the proviso that X and A are not both N; R.sup.6 is H, halogen,
(C.sub.1-6 alkyl) or OR.sup.7, wherein R.sup.7 is H or (C.sub.1-6 alkyl);
R.sup.1 is selected from the group consisting of 5- or 6-membered
heterocycle having 1 to 4 heteroatoms selected from O, N, and S, phenyl,
phenyl(C.sub.1-3)alkyl, (C.sub.2-6)alkenyl, phenyl(C.sub.2-6)alkenyl,
(C.sub.3-6)cycloalkyl, (C.sub.1-6)alkyl, CF.sub.3, 9- or 10-membered
heterobicycle having 1 to 4 heteroatoms selected from O, N and S, wherein
said heterocycle, phenyl, phenyl(C.sub.2-6)alkenyl and
phenyl(C.sub.1-3)alkyl), alkenyl, cycloalkyl, (C.sub.1-6)alkyl, and
heterobicycle are all optionally substituted with from 1 to 4
substituents; R.sup.2 is selected from (C.sub.1-6)alkyl,
(C.sub.3-7)cycloalkyl, (C.sub.3-7)cycloalkyl(C.sub.1-3)alkyl,
(C.sub.6-10)bicycloalkyl, adamantyl, phenyl, and pyridyl, all of which is
optionally substituted with from 1 to 4 substituents; R.sup.3 is selected
from H, (C.sub.1-6)alkyl, (C.sub.3-6)cycloalkyl,
(C.sub.3-6)cycloalkyl(C.sub.1-6)alkyl, (C.sub.6-10)aryl,
(C.sub.6-10)aryl(C.sub.1-6)alkyl, (C.sub.2-6)alkenyl,
(C.sub.3-6)cycloalkyl(C.sub.2-6)alkenyl,
(C.sub.6-10)aryl(C.sub.2-6)alkenyl, N{(C.sub.1-6)alkyl}.sub.2,
NHCOO(C.sub.1-6)alkyl(C.sub.6-10)aryl, NHCO(C.sub.6-10)aryl,
(C.sub.1-6)alkyl-5- or 10-atom heterocycle, having 1 to 4 heteroatoms
selected from O, N and S, and 5- or 10-atom heterocycle having 1 to 4
heteroatoms selected from O, N and S; wherein said alkyl, cycloalkyl,
aryl, alkenyl and heterocycle are all optionally substituted with from 1
to 4 substituents; n is zero or 1; or a detectable derivative or salt
thereof.The compounds of the invention may be used as inhibitors of
hepatitis C virus replication.The invention further provides a method for
treating or preventing hepatitis C virus infection.
