Nitration Methyl Benzoate

Nitration of Methyl Benzoate Abstract This experiment illustrates an important electrophilic aromatic substitution reaction. The nitration of methyl benzoate involved the use of a sulfuric-nitric acid mixture as well. As a result, 1.13 grams of methyl-3-nitrobenzoate was produced from the reaction. The product had a melting point range of 71.2-75.7°C. The percent yield was 87.6% meaning there was some consistency, but the slightly lower melting point range may have been a result of a few sources of error. Introduction The purpose of this experiment was to highlight an important electrophilic aromatic substitution reaction. This experiment involved the use of concentrated nitric acid and concentrated sulfuric acid. The reaction that took place during the experiment used a substituted aromatic ring that led to the meta nitration of the aromatic ring. The low reactivity of benzene rings usually require the electrophile to be extremely reactive. Nitration is a process that introduces a nitro group into an organic compound. In this experiment, nitration used concentrated nitric acid and concentrated sulfuric acid to generate the nitronium ion electrophile. The final product of the reaction resulted in a crystalline solid with a slightly low melting point. Materials Chemicals  Sulfuric acid  Nitric acid  Methyl benzoate  Ice-cold methanol Apparatus  Test tubes  Glass Pasteur pipette  Glass stirring rod  Small beaker  Ice-cold water  Large beaker with ice and water (ice bath)  Hirsch funnel  Ice  PPE, such as gloves, goggles, and lab coat Experimental Procedure Concentrated sulfuric acid and concentrated nitric acid were carefully combined in a suitable test tube, then placed in an ice bath. Methyl benzoate and concentrated sulfuric acid were added to a second test tube. Once added, the test tube was flicked so the components would mix, and then the mixture was placed in an ice bath. With a glass Pasteur pipette, the sulfuric-nitric acid mixture was added drop-wise to the methyl benzoate mixture. The overall mixture was mixed with a glass stirring rod after each drop. Once the mixture was completely mixed, the mixture was removed from the ice bath and warmed to room temperature. The mixture was let standing for 15 minutes. The mixture was then poured into a small beaker containing ice. The resulting crystallized product was filtered with a Hirsch funnel, and washed out with ice-cold water. After the product was transferred, the product was washed with icecold methanol. The mass and melting point were recorded. Results and calculations The weight of the tray used was 21.99 grams. The weight of the tray with the product was 23.12 grams, meaning the product weighed 1.13 grams. Then the melting point was determined to be 71.2-75.7 degrees Celsius, with an experimental value of 78-80 degrees Celsisus. The moles of methyl benzoate was 0.004 mol. Given the amounts, methyl benzoate was determined to be the limiting reagent. The theoretical yield was 0.99g, while the actual was 1.13g. These amounts gave a percent yield of 87.6%. Discussions Nitration of methyl benzoate took place during this experiment. In this experiment, nitration used concentrated nitric acid and concentrated sulfuric acid to generate the nitronium ion electrophile. The limiting reagent was determined to be the methyl benzoate. This is mainly due to the smaller amount used in contrast to the sulfuricnitric acid used. The weight of the methyl-3-nitrobenzoate was 1.13 grams. This amount is slightly larger than the theoretical amount of 0.99 grams. This could be due to personal error during the filtration of the wet product, or even during the reflux period. The percent yield of 87.6% was high and showed consistency. The end product had a low melting point. The melting point recorded was 71.2-75.7 degrees Celsius, which is slightly lower than the melting point range in the manual, 78-80 degrees Celsius. Conclusion The calculated percent yield was 87.6%. Given the amount, the percent yield was high and consistent. Material Safety Data Sheet Understanding hazards associated with chemicals is an integral component of safe and responsible laboratory practice. Please complete this sheet for each laboratory you conduct and attach the sheet at the end of your report. Attach multiple sheets if using more than six chemicals. MSDS Information Chemical name Concentration (if a pure Amount (mass Complete the Hazard solid, liquid or gas, write or volume) Diamond “pure”) Concentrated liquid 1.6 mL 3 HEALTH sulfuric acid 0 FLAMIBILITY 2 REACTIVITY SPECIAL HAZARD Concentrated nitric liquid 0.4 mL 4 HEALTH acid 0 FLAMIBILITY 0 REACTIVITY SPECIAL HAZARD Methyl benzoate solid 0.6 g 1 HEALTH 2 FLAMIBILITY 0 REACTIVITY SPECIAL HAZARD Methanol liquid 0.5 mL 1 HEALTH 3 FLAMIBILITY 0 REACTIVITY SPECIAL HAZARD HEALTH FLAMIBILITY REACTIVITY SPECIAL HAZARD HEALTH FLAMIBILITY REACTIVITY Special Hazard Symbols: OX – Oxidizer SA – Asphyxiant W - No Water GHS GHS is an acronym for The Globally Harmonized System of Classification and Labelling of Chemicals. The GHS is a system for standardizing and harmonizing the classification and labelling of chemicals. It is a logical and comprehensive approach to: ■ Defining health, physical and environmental hazards of chemicals; ■ Creating classification processes that use available data on chemicals for comparison with the defined hazard criteria; and ■ Communicating hazard information, as well as protective measures, on labels and Safety Data Sheets (SDS). ■ Place a tick next to any image that is relevant to your experiment. For example, if you used sodium hydroxide, you would place a tick in the box containing the corrosion image. Health Hazard Carcinogen Mutagenicity Reproductive Toxicity ☒ Respiratory Sensitizer ☒ Target Organ Toxicity ☒ Aspiration Toxicity ☒ ☒ ☒ Gas Cylinder ☐ Gaseous Under pressure Flame Over Circles ☒ Flame Flammable Pyrophorics Self-Heating Emits Flammable gas ☒ Self-Reactives ☒ Organic peroxides ☒ ☒ ☒ ☒ Corrosion ☒ Skin Corrosion/ Burns ☒ Eye Damage ☒ Corrosive to Metals Environment Oxidizers (NonMandatory) ☐ Aquatic toxicity Exclamation Mark ☒ ☒ ☒ ☒ ☒ ☒ Irritant (skin and ey Skin Sensitizer Acute Toxicity Narcotic effects Respiratory Tract irritant Hazardous to Ozone Layer (Non-Mandatory) Exploding Bomb ☐ Explosives ☐ Self-Reactives ☐ Organic Peroxides Skull and Crossbones ☒ Acute toxicity (fatal or toxic)