Synthesis of N,N-Diethyl-Meta-Toluamide

Purpose :
The purpose of this lab was to synthesize N,N-Diethyl-meta-toluamide (DEET) using the m-methylbenzyoic acid and diethylamine. DEET is the most active ingredient in insect repellents. It is used to protect the skin from insect bites.



Result:
The final weight obtained of the product, N,N-Diethyl-meta-toluamide, was 0.25grams.
The theoretical weight of N,N-Diethyl-meta-toluamide :
Moles of diethyl amine used = moles of N,N-Diethyl-meta-toluamide = 2.50mmol.
Theoretical weight = 2.50mmol x 191.27g/mol
= 0.478grams.
Percent yield of product = 0.25/0.478 x 100%=52.3%
Discussion :
The yield of product was 0.25grams, which was 52.3% of the theoretical yield expected. The discrepancy in the results might have risen from several sources in the experiment.
One possible source might have been a systemic error. All glass wares were required to be dried throughout the experiment and the solutions were expected to be kept cool in order to avoid evaporation of the intermediates. Therefore, the error might have resulted from the use of a wet glassware during the experiment, or if the solutions were left warm during the first part of the experiment.
Conclusion:
The synthesis of N,N-Diethyl-meta-toluamide was feasible with the methods and procedures used in this experiment. The obtained product, though the yield was low, had the physical and chemical properties of the product expected.
This experiment can be improved by using clean and dry glass wares in addition to keeping the initial solutions of diethyl amine cold during the experiment.