Abstract: Apparatus for carrying out a multiplicity of different sequential chemical syntheses on solid-supports simultaneously comprises a multiplicity of complementary support plates each formed with a reaction chamber opening through the plate and containing the solid-support together with at least one by-pass channel through the plate. The by-pass channel or channels and reaction chamber are disposed equi-angularly and at the same radial distance about an axis of the plate. The plates are rotatably supported in compression in face to face contact between end plates complementary to the plates and each formed with a blank position and passages for at least one reactant stream. Means is provided for independently rotating each plate whereby each reaction chamber of each plate may independently be isolated or positioned in the or a selected reactant stream.

Abstract: Compounds corresponding to the following general formula: ##STR1## wherein Ar and Ar.sup.1, which may be the same or different, each represents an aromatic radical which may be substituted one or more times by halogen and/or nitro and/or lower alkyl and/or trihalomethyl and/or cyano and/or lower alkoxy and/or di-lower alkyl-amino, the alkyl groups optionally completing a ring optionally incorporating a further heteroatom, and/or lower alkyl sulphonyl;Alk.sup.1 and Alk.sup.2, which may be the same or different, each represents an alkylene group containing from one to eight carbon atoms which may be substituted one or more times by aryl and/or cycloalkyl and/or lower alkyl and if two such alkyl groups are present, they may complete a ring optionally containing a heteroatom and in which imidazole ring may be further substituted; and m represents 0 or 1; provided that not both Ar and Ar.sup.1 represent phenyl; and acid addition salts thereof.