LA MARAST

LaMarast is a synthesizer for manual solid phase synthesis that uses a simple concept for draining and filling reaction vessels. The same concept is used in the Domino Blocks synthesizer. Enclosed reaction vessel is connected to an evacuated waste container. Any liquid present in the reaction vessel is drawn into the waste container and the reaction vessel is evacuated at the same time. The evacuated reaction vessel is then connected to a reservoir with washing solvent. The solvent is drawn from the reservoir (which is under atmospheric pressure) into the evacuated reaction vessel. When sufficient amount of washing liquid was introduced, the reaction vessel is connected to air (or inert gas) to equilibrate the pressure inside the reaction vessel with the atmospheric pressure.

Conical centrifuge tubes with volume 100 mL, 200-mL, and 450-mL serve as reaction vessels (see the Picture). Single outlet reaction vessels of three sizes handle from 3 to 30 g of resin. The female Luer bulkhead fitting with external thread was attached to the cap. Teflon tubing 1/8" connected the fitting with the porous polypropylene cylinder. The reaction vessels were placed into custom made holders (high density polyethylene). The footprint of holders matched the standard 96-well plate. This allowed using commercially available plate shakers rather that a special custom build shaker.

In order to operate the La Marast synthesizer with four reaction vessels a panel with three four-port distribution Teflon valves was used (see Scheme). Four reaction vessels were connected using Teflon 1/8" tubing with four ports of the V1 valve. The common port of the V1 valve was connected to the common port of the four-port V2 valve. The port on the right hand side was connected to the evacuated waste container. Empty syringe was attached to the upper port of the V2 valve. The lower port was left empty. The left hand side port was connected to the common port of the V3 valve. The four ports of this V3 valve were connected to four reservoirs with solvents. All connections and vetted parts of valves were made of Teflon. The disposable reaction vessels were made of polypropylene. If dictated by a chemical protocol, Teflon made reaction vessel was used.

The synthesizer La Marast consists of four reaction vessels (please, specify the size) with caps including fritted cylinders, four reaction vessel holders, a stand with three Teflon valves, and connecting Teflon tubing. The reaction vessel includes cap with fitting, fritted cylinder, and Teflon tubing. Simple clamps are used to secure the position of a holder on the shaker platform (see picture).