Imidazole derivatives for pharmaceutical use

A medicament acting as an antagonist of the H.sub.3 receptors of histamine containing a compound selected from the group consisting of a compound of the formula ##STR198## in which A is a hydrocarbon chain containing 1 to 6 carbon atoms uninterrupted or interrupted by a heteroatom selected from the group consisting of --S--, --O-- and --NH--;

• X is selected from the group consisting of oxygen, sulfur, --CO--, --NH--, --NHCO--, --N(alkyl)CO--, NHCONH--, --NHCS--, --O--CO--, --CO--O--, --OCONH--, --OCON(alkyl)--, --OCONH-- --CONH--, --CON(alkyl)--, --SO--, --CHOH-- and --NR--C(.dbd.NR")--NR'--;
• R and R' are hydrogen or lower alkyl;
• and R" is selected from the group consisting of hydrogen, cyano and --COY.sub.1, Y.sub.1 is alkoxy;
• B is selected from the group consisting of --(CH.sub.2).sub.n --, n is an integer from 0 to 5, a branched alkylene of 2 to 8 carbon atoms uninterrupted or interrupted by at least one oxygen or sulfur, --(CH.sub.2).sub.n --O--, and --(CH.sub.2).sub.n' --S--, where n' is an integer of 1 or 2;
• Y is selected from the group consisting of alkyl of 1 to 8 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, bicycloalkyl, cycloalkenyl, aryl, 5- or 6-membered heterocycle selected from the group consisting of pyridyl, N-oxide-pyridyl, pyrimidinyl, and pyrazinyl unsubstituted or substituted with at least one member of the group consisting of --NO.sub.2, --CF.sub.3, --CH.sub.3, --NH.sub.2, halogen, --COOCH.sub.3, imidazolyl, thiazolyl, and a bicyclic formed by a heterocycle as defined above to which a phenyl ring is fused;
• with the proviso that, when X is --NH-- and A is a straight saturated hydrocarbon chain containing 1 to 6 carbon atoms, B cannot be a straight alkylene chain and Y cannot be phenyl or imidazolyl;
• with the proviso that, when X is --NH-- and A is --(CH.sub.2).sub.2 --, B and Y cannot simultaneously be --(CH.sub.2).sub.2 --O-- or --(CH.sub.2).sub.n --S-- and phenyl or p-chlorophenyl;
• with the proviso that when X is --NH-- and A is a straight saturated hydrocarbon chain of 1 to 6 carbon atoms, Y cannot be substituted or unsubstituted aryl (formula IB), and when X is --NH-- and A is --CH.sub.2 -- in formula IA, B and Y cannot simultaneously be --CH.sub.2 -- and 2,6-dimethylphenyl;
• with the proviso that when X is --NH-- and A is --(CH.sub.2).sub.2 --, B and Y cannot simultaneously be --CH(C.sub.1 -C.sub.3 alkyl)--CH.sub.2).sub.n -- (n=1 to 4) and methyl or substituted or unsubstituted phenyl in formula IA and Y cannot be --(CH.sub.2)6-- in the formula IB;
• with the proviso that, when X is --NHCONH-- and A is a straight saturated hydrocarbon chain of 1 to 6 carbon atoms, B and/or Y cannot be alkyl, and Y cannot be aryl;
• with the proviso that, when X is --NHCO-- and A is --(CH.sub.2).sub.2 --, Y in formula IB cannot be methyl or substituted cyclohexyl, or Y cannot be para-nitrophenyl or para-amino-phenyl, B and Y in formula IA cannot simultaneously be --(CH.sub.2).sub.n --, n being an integer of 1 to 6, --CH.sub.2 --O--, or --CH.sub.2 S--CH.sub.2 -- and phenyl, or --CH.sub.2 --CH.sub.2 -- or --CH.sub.2 --S--CH.sub.2 -- and diphenyl or --(CH.sub.2).sub.3 -- or --CH.sub.2 --S--CH.sub.2 and pyridyl, or --CH.sub.2 --CH.sub.2 -- or --CH.sub.2 --S-- and diphenyl or --(CH.sub.2).sub.3 -- and imidazolyl or cyclohexyl;
• with the proviso that, when X is --NHCO-- and A is --CH.sub.2 --CH(CH.sub.3)--, B and Y cannot simultaneously be --(CH.sub.2).sub.3 -- and phenyl;
• with the proviso that, when X is --NHCONH-- and A is --(CH.sub.2).sub.2, B and Y cannot simultaneously be --CH.sub.2 --CH.sub.2 -- and phenyl;
• with the proviso that, when X is oxygen and A is --CH.sub.2 --, Y in formula IB cannot be substituted phenyl;
• with the proviso that, when X is --CO-- and A is --(CH.sub.2).sub.2 --, Y in formula IB cannot be substituted or unsubstituted aryl;
• with the proviso that, when X is --CO-- and A is methylene, B and Y cannot simultaneously be --C(CH.sub.3).sub.2 --(CH.sub.2).sub.n -- (n=0 or 1) and substituted or unsubstituted aryl;
• with the proviso that, when X is --CONH-- and A is --(CH.sub.2).sub.2 --, Y in formula IB cannot be substituted or unsubstituted phenyl;
• with the proviso that, when X is --NH--C(.dbd.NCN)--NH--, A and B are hydrocarbon chains of 2 to 5 carbon atoms interrupted or uninterrupted by S or O, Y cannot be pyridyl, imidazolyl, or thiazolyl;
• with the proviso that, when X is --NH--C(.dbd.NCN)--NH-- and A is --CH.sub.2 --S--(CH.sub.2).sub.2 --, Y in formula IB cannot be methyl;
• with the proviso that, when X is --NH--C(.dbd.NH)--NH--, Y cannot be alkyl or aryl;
• with the proviso that, when X is --NH--C(.dbd.NH)--NH--, A is --(CH.sub.2).sub.n -- (n=2 or 3), Y cannot be pyridyl, imidazolyl, benzimidazolyl or quinolyl in formula IA;
• with the proviso that, when X is --NH--C--(.dbd.NCOY.sub.1)--NH-- and A is hydrocarbon of 2 to 5 carbon atoms interrupted by 0 or S, Y cannot be alkyl;
• with the proviso that, when X is --NH--C(--NCOY.sub.1)--NH--, A is --(CH.sub.2).sub.n -- (n=2 or 3) and B is --(CH.sub.2).sub.n -- (n=2 to 5) or a branched alkylene chain of 3 to 6 carbon atoms optionally interrupted or uninterrupted by oxygen or sulfur, or --(CH.sub.2).sub.2 --O-- or (CH.sub.2).sub.2 --S--, Y cannot be substituted or unsubstituted aryl or pyridyl, imidazolyl, benzimidazolyl or quinolyl;
• with the proviso that, when X is --NH--C(=NCOY.sub.1)--NH--, A is --(CH.sub.2).sub.n -- (n=2 or 3), Y in formula IB cannot be pyridyl;
• with the proviso that, when X is NH and Y is alkyl, A is neither --(CH.sub.2).sub.2 -- nor --(CH.sub.2).sub.3 --;
• and a pharmaceutically acceptable salt, hydrate, hydrated salt, polymorphic crystalline structures of the tautomeric forms thereof, in the presence or absence of a therapeutically acceptable vehicle or excipient.