Abstract: The present invention relates to new D3 and D2 dopamine receptor subtype preferring ligands of formula (I): wherein R1 and R2 represent independently a substituent selected from hydrogen, alkyl, aryl, cycloalkyl, aroyl, or R1 and R2 may form a heterocyclic ring with the adjacent nitrogen atom; X represents an oxygen or sulphur atom; n is an integer of from 1 to 2, and/or geometric isomers and/or stereoisomers and/or diastereomers and/or salts and/or hydrates and/or solvates thereof, to the processes for producing the same, to pharmaceutical compositions containing the same and to their use in therapy and/or prevention of a condition which requires modulation of dopamine receptors.

Abstract: The invention relates to the new monohydrate of N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N"-cyanoguanidi ne (cimetidine), a histamine-H.sub.2 receptor antagonist which is called N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N"-cyanoguanidi ne H (cimetidine H) as well as to a process for the preparation of same, which comprises pouring a hot, homogeneous aqueous solution of N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N"-cyanoguanidi ne, optionally containing also methylamine, onto ice and separating the N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N"-cyanoguanidi ne monohydrate.

Abstract: The invention relates to a new crystal modification of N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N"-cyanoguanidi ne (cimetidine), a histamine H-2 receptor antagonist having the Formula (I) ##STR1## as well as to a process for preparing same. In the description, this new modification is named N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N"-cyanoguanidi ne Z (cimetidine Z).