The Nitration of Methyl Benzoate free essay sample

Introduction The purpose of this experiment is to synthesize methyl nitrobenzoate from methyl benzoate, concentrated HNO3, and concentrated H2SO4 via an electrophilic aromatic substitution reaction. Reaction Procedures/ Observations Use a 50 ml beaker to cool about 6 ml of concentrated sulfuric acid in an ice water bath. Weigh the vial containing about 3 grams of methyl benzoate and add it to the cooled sulfuric acid. Next pour about 2 ml of sulfuric acid to the nitric acid in the vial and allow for it to cool. After mixture is cooled add it drop wise to the cooled sulfuric acid/methyl benzoate mixture making sure the temperature remains under 15 degrees Celsius. Allow mixture to cool to room temperature and pour it over 25 g of ice and allow the ice to melt. Next isolate the product by vacuum filtration and weigh the crude product. Recrystallize the product from equal weight of methanol. Place mixture in water bath and heat it up so the solid dissolves. We will write a custom essay sample on The Nitration of Methyl Benzoate or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Next allow for solution to cool to room temperature and perform vacuum filtration again and then wash the solid with methanol. Allow product to air dry for a week. The following week weigh the clean vial and cap and transfer the product to vial and weigh it. Finally, determine the melting point. Results and conclusions In this experiment 5. 9 ml of sulfuric acid, 2. 1 ml of nitric acid, and 1. 8 ml of sulfuric acid was used. The amount of methyl benzoate obtained was 2. 972 grams, and 3. 90 grams of methyl m- nitrobenzoate product was also acquired. The limiting reagent for this electrophilic aromatic substitution reaction is methyl benzoate. It yields the least amount of methyl nitrobenzoate in this reaction, and therefore is the limiting reagent. The electrophilic aromatic substitution reaction between methyl benzoate and a nitrating solution of sulfuric and nitric acids was successful and yielded methyl m-nitrobenzoate. The percent yield of the recrystallized product was 93%. The observed melting point of 68 70Â °C was fairly close to the literature melting point of 78 – 80Â °C for a meta substituted product. Therefore, my product is a meta-product. The meta-product forms because the ortho- and para- products both have very unstable resonance forms with two positive charges next to each other. The two positive charges right next to one another causes the resonance forms to be unstable, so ortho- and para- substituted products do not form in this reaction.