Nitration of Methyl Benzoate
Sarah Muhs
ID: 11325862
Nitration of Methyl Benzoate
Post Lab:
1. Is the ester group of your starting material electron donating or withdrawing? Support your conclusion with resonance drawings.
The ester group, CO2CH3, of the starting material was electron withdrawing.
2. Draw the mechanism of the nitronium ion reaction with the methylbenzoate.
3. Why does water stop the reaction?
Water stops the reaction because of Le Châtlier’s principle. Since water is a product, when more is added it drives the reaction to the reactant side. More nitric acid is produced, which is not a strong enough electrophile to react with methyl benzoate, which stopped the reaction.
4. According to your TLC plate, how many products did your reaction produce and which isomers are produced?
My reaction produced two products. The isomers produced were ortho and meta. Both spots that appeared on the plate were similar in size, showing that the ortho and meta isomers were produced in somewhat equal amounts.
Conclusions:
In this experiment, I started by adding 560 µL of sulfuric acid to a 5mL conical vial that contained a conical spin vane. This conical vial was then placed into an ice bath to cool for five minutes. I then obtained two small disposable test tubes. In the first, I combined 240µL of nitric acid and 240µL of sulfuric acid. The second test tube contained 3 mL of deionized water. These were then placed into an ice bath. After five minutes, the conical vial was removed from the ice bath and placed into a stir plate. While the sulfuric acid solution in the vial was stirring, the
200µL of methyl benzoate was added dropwise using a Pasture pipette. After the methyl benzoate was added, the cold nitric acid/sulfuric acid mixture was added to the conical vial dropwise. The solution was then left to stir at room temperature for 15 minutes. After the allotted time, the reaction was stopped by adding approximately 2 mL of de-ionized water. Then the spin vane was extracted from the vial
ID: 11325862
Nitration of Methyl Benzoate
Post Lab:
1. Is the ester group of your starting material electron donating or withdrawing? Support your conclusion with resonance drawings.
The ester group, CO2CH3, of the starting material was electron withdrawing.
2. Draw the mechanism of the nitronium ion reaction with the methylbenzoate.
3. Why does water stop the reaction?
Water stops the reaction because of Le Châtlier’s principle. Since water is a product, when more is added it drives the reaction to the reactant side. More nitric acid is produced, which is not a strong enough electrophile to react with methyl benzoate, which stopped the reaction.
4. According to your TLC plate, how many products did your reaction produce and which isomers are produced?
My reaction produced two products. The isomers produced were ortho and meta. Both spots that appeared on the plate were similar in size, showing that the ortho and meta isomers were produced in somewhat equal amounts.
Conclusions:
In this experiment, I started by adding 560 µL of sulfuric acid to a 5mL conical vial that contained a conical spin vane. This conical vial was then placed into an ice bath to cool for five minutes. I then obtained two small disposable test tubes. In the first, I combined 240µL of nitric acid and 240µL of sulfuric acid. The second test tube contained 3 mL of deionized water. These were then placed into an ice bath. After five minutes, the conical vial was removed from the ice bath and placed into a stir plate. While the sulfuric acid solution in the vial was stirring, the
200µL of methyl benzoate was added dropwise using a Pasture pipette. After the methyl benzoate was added, the cold nitric acid/sulfuric acid mixture was added to the conical vial dropwise. The solution was then left to stir at room temperature for 15 minutes. After the allotted time, the reaction was stopped by adding approximately 2 mL of de-ionized water. Then the spin vane was extracted from the vial