Sn1 Sn2 Reactions
Experiment 15 & 16: Preparation of 1-bromobutane, an SN2 reaction
Preparation of 2-chloro-2-methylbutane, an SN1 reaction
Introduction
The purpose of this experiment is to synthesize 1-bromobutane from 1-butanol and sodium bromide. In order for this reaction to reach completion there are four major operations that need to be performed. The four major operations include refluxing, simple distillation, separation, and drying. To begin, in order for the compounds to react they will be dissolved in water and sulfuric acid will be added. The addition of sulfuric acid will then generate hydrobromic acid, an important product in the reaction mixture. The hydrobromic acid will react with the 1-butanol when heat is added to the flask during refluxing. Refluxing is the heating of a flask to boiling and then allowing the vapors to condense and run back into the reaction flask. Refluxing is a good way of keeping a reaction at a constant temperature. After refluxing is complete the reaction is distilled by the method of simple distillation. The simple distillation process is used to help remove and purify a particular substance, in this case the 1-bromobutane, from other components in the reaction flask. However, since the boiling point of 1-bromobutane is 101°C and the boiling point of water is 100°C it would be expected that there would be a large amount of water that will distill out of the flask along with 1-bromobutane. Other remaining reactants such as a small amount of alcohol and/or acid may be distilled out along with the water of 1-bromobutane. Since there is such a high probability of other components in the distillate, separation processes will need to be carried out. Water is first added to the 1-bromobutane layer to remove any leftover starting material and after the 1-bromobutane layer is isolated sodium hydroxide, water, and sodium chloride solutions are added to remove any remaining acid. Drying using anhydrous sodium sulfate is then used to
Preparation of 2-chloro-2-methylbutane, an SN1 reaction
Introduction
The purpose of this experiment is to synthesize 1-bromobutane from 1-butanol and sodium bromide. In order for this reaction to reach completion there are four major operations that need to be performed. The four major operations include refluxing, simple distillation, separation, and drying. To begin, in order for the compounds to react they will be dissolved in water and sulfuric acid will be added. The addition of sulfuric acid will then generate hydrobromic acid, an important product in the reaction mixture. The hydrobromic acid will react with the 1-butanol when heat is added to the flask during refluxing. Refluxing is the heating of a flask to boiling and then allowing the vapors to condense and run back into the reaction flask. Refluxing is a good way of keeping a reaction at a constant temperature. After refluxing is complete the reaction is distilled by the method of simple distillation. The simple distillation process is used to help remove and purify a particular substance, in this case the 1-bromobutane, from other components in the reaction flask. However, since the boiling point of 1-bromobutane is 101°C and the boiling point of water is 100°C it would be expected that there would be a large amount of water that will distill out of the flask along with 1-bromobutane. Other remaining reactants such as a small amount of alcohol and/or acid may be distilled out along with the water of 1-bromobutane. Since there is such a high probability of other components in the distillate, separation processes will need to be carried out. Water is first added to the 1-bromobutane layer to remove any leftover starting material and after the 1-bromobutane layer is isolated sodium hydroxide, water, and sodium chloride solutions are added to remove any remaining acid. Drying using anhydrous sodium sulfate is then used to
Cited: 1) Gilbert, John, C., Martin, Stephen, F. Experimental Organic Chemistry: A Miniscale and Microscale Approach. 5th ed. Brooks/Cole. 2011. Print.