Microwave Synthesis of Novel Esters Using Sulfuric Acid and Imidazole as Catalysts

Abstract

As recent literature indicates, microwaves are quickly becoming an accepted tool for investigators in the organic laboratory. Microwave synthesis enables reactions to proceed more rapidly with greater yields than many conventional techniques. In this research we have investigated the synthesis of several esters using a conventional microwave oven and a new method of purification. We compared these syntheses using both sulfuric acid and imidazole as catalysts, as well as a comparison of acid and acid anhydride products. It was hypothesized originally that the esters could be synthesized using the imidazole as a catalyst with any acid. However, we found that we were not able to obtain product without using anhydride acids. Also, for purification, we found it more efficient for the Sulfuric catalyzed esters to first be mixed with ether and then to wash the mixture with sodium bicarbonate then sodium hydroxide, draining and discarding the lower layer each time. When this is done sodium bicarbonate removes any excess sulfuric and the sodium hydroxide removes excess acid.