An apparatus and method which provides a suitable location for multiple, simultaneous synthesis of compounds. The apparatus 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. The apparatus provides in excess of 1 mg of each product with structural knowledge and control over each compound. Using the apparatus a series of building blocks are covalently attached to a solid support. These building blocks are then modified by covalently adding additional different building blocks or chemically modifying some existing functionality until the penultimate structure is achieved. This is then cleaved from the solid support by another chemical reaction into the solution within the well yielding an array of newly synthesized individual compounds, which after postreaction modification, if necessary, are suitable for testing for activity.