Hydroxyanidino derivatives useful as nitric oxide synthase inhibitors

A compound having the formula;

• ##STR11## and pharmaceutically acceptable salts, wherein:
• R.sub.1 is not present or is selected from the group consisting of hydrogen, hydroxyalkyls, alkoxyalkyls, lower alkyls and haloalkyls;
• R.sub.2 is selected from the group consisting of straight and branched lower alkyls, lower alkenyls, and lower alkynyls, cycloalkyls, cycloalkenyls, and haloalkyls;
• R.sub.3 is selected from the group consisting of hydroxy, lower alkoxys, and natural and synthetic amino acids;
• X is selected from the group consisting of lower alkylenes, lower alkenylenes and lower and which may optionally be substituted by one or more alkyl, alkoxy, hydroxy, halogen, trifluoromethyl, nitro, cyano, or amino groups;
• or
• X is selected from the group consisting of the formula --(CH.sub.2).sub.k Q(CH.sub.2).sub.t -- where k is 1, 2 or 3, t is 1, 2 or 3 and Q is O, Se, SiY.sub.2 where Y is lower alkyl, aryl, S(O).sub.Z where z is 0, 1 or 2, or NR where R is H or lower alkyl which may be optionally substituted with lower alkyl, lower alkoxy, hydroxy, halogen, trifluoromethyl, nitro, cyano, amino;
• or
• X is selected from the group consisting of the formula --(CH.sub.2).sub.m A(CH.sub.2).sub.n -- where m is 0, 1 or 2, n is 0, 1 or 2, A is a 3 to 6 membered carbocyclic or heterocyclic ring, aromatic ring or heteroaromatic ring which may optionally be substituted by one or more substituents selected from the group consisting of lower alkyl, lower alkoxy, hydroxy, halogen, nitro, cyano, trifluoroalkyl and amino.