Assembly of a Reflux System for Heated Chemical Reactions

1. Preparation of Glassware

1. Ensure the glassware is free of chemical contaminants and if necessary of moisture by allowing to heat in an oven at 100 °C for approximately 30 min.
2. Once cooled, ensure all ground glass joints are contaminant free using either a dry or acetone soaked cleaning tissue specially made for laboratory applications.
3. After dissolving regents in a suitable solvent in an appropriate reaction vessel (typically a round-bottomed flask) and adding a magnetic stirrer bar, connect the reflux condenser and reaction vessel via the ground glass joint.  Attach a Keck clip to the joint.
4. Attach tubing from a cold-water tap to the bottom-most inlet of the reflux condenser and another piece of tubing from the top-most outlet to a sink. Start flowing cold water through the outer jacket of the condenser at such a rate that the sink does not overfill.

2. Heating of Reactants

1. Using a hotplate stirrer, submerge the reaction vessel into a heating bath (oil or water) until the level of the bath is just above the level of the solution within the vessel and hold in place using a ring stand, clamp, and boss.
2. Start stirring the reaction. Heat the bath to about 15 °C over the boiling point of the solvent. Once equilibrium between evaporation and condensation has been reached a steady drip of condensed solvent will start falling back into the reaction vessel from the condenser column.

3. Dismantling the Apparatus

1. Once the desired time has passed remove the reaction vessel/reflux apparatus from the bath by clamping it higher up the ring stand.
2. Allow the water to continue flowing through the reflux condenser until the solution has reached room temperature.
3. Turn off the flow of water and disconnect the condenser from the reaction vessel.
4. Empty any remaining water in the condenser into the sink and remove tubing from inlet and outlet.