The present invention is directed to a compound of formula I:
##STR1##
or a pharmaceutically acceptable salt thereof, wherein:
R2 is selected from the group consisting of H and methyl; and
R2 is selected from the group consisting of H and methyl.
The compounds possess useful nitric oxide synthetase inhibiting activity, and
are expected to be useful in the treatment or prophylaxis of a disease or condition
in which the synthesis or over synthesis of nitric oxide forms a contributory part.
