PREPARATION OF METHYL BENZOATE

DAY 1

1. Place 10-gm benzoic acid and 25-mL methanol into a 100-mL round-bottomed flask.

2. From the repipettor, carefully add 3-mL conc. H₂SO₄ down the side of the flask.

3. Swirl the flask to mix the reagents

4. Attach a reflux condenser, and gently reflux for one hour.

5. Transfer the solution in the flask to a 250-mL separatory funnel containing 50-mL water.

6. Rinse the flask with 40-mL diethyl ether and add the rinsing to the funnel.

7. Shake the funnel thoroughly, ( venting the funnel frequently ), to facilitate extraction

of the methyl benzoate into the ether layer.

8. Remove the aqueous layer and wash the organic layer with a second 25-mL portion of

water.

9. Separate the layers, (leaving the organic layer in the funnel), and cautiously add 25-mL

0.6M NaHCO₃ to the organic layer remaining in the funnel.

10. Shake the mixture, (venting frequently), to wash the product of any remaining acids.

( Which acid(s) ?).

11. Remove the aqueous layer and test to see it is basic to litmus. If not, Wash the organic

layer with another 25-mL portion of NaHCO₃ and test the aqueous wash again with

litmus.

12. Once the NaHCO₃ wash is basic to litmus, wash the organic layer a final time with

Saturated NaCl. (why ?).

13. Dry your product over anhydrous MgSO₄.

14. Decant the dried organic layer into your cleaned and dried 100-mL round-bottomed

flask and simple distill off the remaining ether, using a low heat setting on your heating

mantle.

15. Allow the flask to cool and weigh the product.

16. Save this product for use in the Grignard Experiment.