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.

Preparation of Aldol Condensation Product

Purpose :
The purpose of this lab was to synthesize 2,6-Dibenzalcyclohexanone using an aldo condensation reaction between benzaldehyde and cyclohexanone. The product will be recrystallized using 95% ethanol, then characterized using melting point analysis.



Result:
The final weight of product obtained from the aldo condensation reaction was 0.42g of 2,6-Dibenzalcyclohexanone. The melting point obtained of the product was 108°C . The actual melting point of 2,6-Dibenzalcyclohexanone,however, is 120°C .
The theoretical weight of the product is
Grams of 2,6-Dibenzalcyclohexanone =
moles of 2,6-Dibenzalcyclohexanone x molecular weight of 2,6-Dibenzalcyclohexanone
moles of 2,6-Dibenzalcyclohexanone = moles of ketone used = 0.002mols
Theoretical weight = 274.36grams/mols x 0.002mols = 0.548grams.
Therefore, percent yield of product :
0.42/0.55 x 100%=76.5%

Discussion :
The yield of the product was 76.5% of 2,6-Dibenzalcyclohexanone, and the melting point was 108°C, which was about 12°C different from the actual melting point expected of the product. This discrepancy in result is due to some errors from the procedures. One source of the error may have been from the transfer of the product from one beaker to another after the reaction. During the process of transfer, some of the product may have been lost, which contributed to the lower yield of the product. Nonetheless, the product obtained was 2,6-Dibenzalcyclohexanone because it had similar properties.

Conclusion:
The purpose of theis experiment, which was to synthesize 2,6-Dibenzalcyclohexanone was accomplished with the method and procedure used in the experiment even though the yield was lower than expected. This experment, however, could be improved if the experiment is designed in such a way that tranferring product from one

Preparation of Para Red and Related Azo dyes

Purpose :
The purpose of this lab was to prepare two azo dyes, para red using a reaction of p-nitroaniline and 2-naphthol, and a related azo dye. Para dye is a chemical dye used in printing. It dyes cellulose fabrics to red.


[reaction diagram for the other azo dye is missing]

Result:
The reaction yielded the desired product, para red, a red colored dye with the use of p-nitroaniline and 2-naphthol.
The second reaction with p-anisidine and 1-naphthol yielded a darker red colored azo dye solution.

Discussion :
The first synthesis using the ketone, 2-napthol, and aldehyde,nitroaniline, produced a red colored para red solution while the other reaction with p-anisidine and 1-naphthol produced a darker red colored solution. The difference in colors of both azo dye was because of the difference in the attachment of the hydroxyl group to the compound. 1-naphthal contains a hydroxyl group on the first carbon, ortho to the attached benzo group while 1-naphthol contains a hydroxyl group on it’s second carbon, meta to the attached benzo group. The difference in color change can also been as a result of the aldehydes used in the solutions.

Conclusion:
The synthesis of para red , and a similar azo dye were achieved through the experimental procedures undertaken, and the products were similar to the predicted azo dyes. The use of similar molecules with different hydroxyl positions reflected on the end result of the solution. However, this experiment may still be improved by careful division of the solutions prior to mixing both solutions because the experiment is skewed if too much of one carbonyl compound is added to the other.