Abstract: Use of a compound of formula (A), wherein: W is a residue which imparts antagonistic and/or agonistic activity at histamine H3-receptors when attached to an imidazole ring in 4(5) position; R1 and R2 may be identical or different and represent each independently a lower alkyl or cycloalkyl, or taken together with the nitrogen atom to which they are attached, a saturated nitrogen-containing ring (i) as defined, a non-aromatic unsaturated nitrogen-containing ring (ii) as defined, a morpholino group, or a N-substituted piperazino group as defined for preparing medicaments acting as antagonists and/or agonists at the H3-receptors of histamine.

Abstract: Process for the synthesis of .alpha.-substituted acrylic acids of general formula (I) and their application to the synthesis of N-(mercaptoacyl)aminoacid derivatives of formula (II).

Abstract: New amino acid derivatives, processes for their preparation and their therapeutic application.Amino acid derivatives corresponding to the general formulae ##STR1## These derivatives may be used as medicaments which exhibit an enkephalinase-inhibitory activity.