An apparatus for multiple, simultaneous synthesis of compounds which consists of: a reservoir block having a plurality of wells; a plurality of reaction tubes, usually gas dispersion tubes, having filters on their lower ends; a holder block, having a plurality of apertures; and a manifold, which may have ports to allow introduction/maintenance of a controlled environment. The manifold top wall has apertures and a detachable plate with identical apertures. The apparatus is constructed from materials which will accommodate heating, cooling, agitation, or corrosive reagents. Gaskets are placed between the components. Rods or clamps are provided for fastening the components together. Apparatus operation involves placing the filters on the lower ends of the reaction tubes in the reservoir block wells, and the upper ends passing through the holder block apertures and into the manifold.