Heating Under Reflux: Syntehsis of Salicylic Acid from wintergreen oil

Purpose: To prepare salicyclic acid from the methyl salicylate and find out whether or not it differs chemically from that made directly from benzene. In this experiments we will determine if there are synthetic pathways that cause product formation differences. We will carry out an organic synthesis, the preparation of salicylic acid from methyl salycilate.. An alkaline environment will push the reacting material in the forward direction through addition of a hydroxyl group, and loss of a methoxy portion of the molecule. The bond breaking and forming will cause the reaction to take more time than that of a inorganic reaction due to the energy barriers it must overcome in bond breaking and making. The product requires purification form the residual contaminants and analysis to determine its purity.

Methyl Salicylate is the limiting reagent within the reaction. NaOH will be used in excess to push the reaction in the forward which is previously established by le Chateliers principle.

The reaction ill be carried out in a round bottom flask boiling the mixture of methyl salicylate and NaOH. Condensers for the liquid will be placed at the other end of the cooling tube to convert the final product gas into its liquid form. The product will contain a salt. Addition of a strong acid will encourage the salt to form into the salicylic acid.

Procedure

1. obtain an appropriate heat source and position correctly.
2. Assemble an apparatus for heating under reflux using a standard taper glassware if available.
3. Make sure the apparatus is clamped securely to the ring stand.
4. Measure 10mmol of methyl calicylate into the boiling flask followed by 15ml of 6m NaOh and a few boiling chips.
5. Don’t add both reactants through the same funnel
6. State water flowing into the condenser jacket then have the instructor check your apparatus before you begin heating.
7. Heat the reaction mixture under reflux for 30 minutes. Measure the heat and boiling times in which you