Rxn Of Iodoethane With SodiumSaccharin
Introduction
The purpose to of this experiment is to carry out the alkylation of sodium saccharin with iodo-ethane and analyze the product mixture to determine the structure of the major product. Sodium saccharin is made from the base catalyzed de protonation of saccharin. This nucleophilic reaction is special because the nucleophilic atom can be oxygen or nitrogen and the leaving group is iodide ion.
The solvent used in this reaction is very important for determining the rate of nucleophilic substitution reaction. Polar protic solvents such as water and ethanol result in bulky solvation shells around the charged nucleophile; this is what reduces its nucleophilic strength. The result is a slower reaction. Polar aprotic solvents do not solvate the nucleophile very strongly, this results in an attack on the substrate. Therefore, polar aprotic solvents accelerate the rates of reaction, especially SN2 reactions, where the strength of the nucleophile determines the rate of reaction.
As far as the reaction properties are concerned, nucleophilic attack by nitrogen on iodoethane yields N-ethylsaccharin, whereas nucleophilic attack by oxygen yields O-ethylsaccharin. The product can be either of these combination of both saccharin. Determining the final product may be difficult but there are some properties which are used. For instance, N-ethylsaccharin is more stable than O-ethylsaccharin, so this should be the major product if the reaction reaches thermal equilibrium. Another factors is the partial charges on the oxygen versus the nitrogen. Oxygen is more electronegative, therefore it has a higher partial negative charge. This indicates that the reaction with the oxygen nucleophile should occur at a faster rate. The final product is determined by using proton nuclear magnetic resonance (H NMR).
Oxygen appears farther downfield on an NMR because of its ability to deshield protons (4.7 ppm). Nitrogen will appear around 3.9 ppm and methlylene protons which
The purpose to of this experiment is to carry out the alkylation of sodium saccharin with iodo-ethane and analyze the product mixture to determine the structure of the major product. Sodium saccharin is made from the base catalyzed de protonation of saccharin. This nucleophilic reaction is special because the nucleophilic atom can be oxygen or nitrogen and the leaving group is iodide ion.
The solvent used in this reaction is very important for determining the rate of nucleophilic substitution reaction. Polar protic solvents such as water and ethanol result in bulky solvation shells around the charged nucleophile; this is what reduces its nucleophilic strength. The result is a slower reaction. Polar aprotic solvents do not solvate the nucleophile very strongly, this results in an attack on the substrate. Therefore, polar aprotic solvents accelerate the rates of reaction, especially SN2 reactions, where the strength of the nucleophile determines the rate of reaction.
As far as the reaction properties are concerned, nucleophilic attack by nitrogen on iodoethane yields N-ethylsaccharin, whereas nucleophilic attack by oxygen yields O-ethylsaccharin. The product can be either of these combination of both saccharin. Determining the final product may be difficult but there are some properties which are used. For instance, N-ethylsaccharin is more stable than O-ethylsaccharin, so this should be the major product if the reaction reaches thermal equilibrium. Another factors is the partial charges on the oxygen versus the nitrogen. Oxygen is more electronegative, therefore it has a higher partial negative charge. This indicates that the reaction with the oxygen nucleophile should occur at a faster rate. The final product is determined by using proton nuclear magnetic resonance (H NMR).
Oxygen appears farther downfield on an NMR because of its ability to deshield protons (4.7 ppm). Nitrogen will appear around 3.9 ppm and methlylene protons which