Electrophilic aromatic substitution Essays

Electrophilic Aromatic Substitution 5. Introduction In this experiment, the directing effects of a bromo substituent was observed in the nitration by an electrophilic aromatic substitution reaction. The nitration was done with the addition of a nitric acid and sulfuric acid solution to bromobenzene, which was an exothermic reaction. When the reaction subsided, the mixture was heated before it was poured on ice and then neutralized to a pH of 8 with sodium carbonate. Liquid-liquid extraction was

When an aromatic compound such as phenol undergoes nitration, it does so through an Electrophilic Aromatic Substitution (EAS). Undergoing this reaction requires two steps. The first step is the addition of the electrophile, which in this lab was the Nitronium ion formed by the dilute nitric acid solution. This is the rate determining step for this reaction, as during this step aromaticity is lost and the arenium ion is formed. The position of the electrophile to be added is determined by how well

The purpose of this experiment was to learn about the electrophilic aromatic substitution reactions that take place on benzene, and how the presence of substituents in the ring affect the orientation of the incoming electrophile. Using acetanilide, as the starting material, glacial acetic acid, sulfuric acid, and nitric acid were mixed and stirred to produce p-nitroacetanilide. In a 125 mL Erlenmeyer flask, 3.305 g of acetanilide were allowed to mix with 5.0 mL of glacial acetic acid. This mixture

observed. Electrophilic aromatic substitution is the reaction of an electrophile with an aromatic ring to form a new bond between the aromatic ring and the electrophile. Two experiments were performed. First, the preparation of 4-nitro-1-bromobenzene takes place through a nitration of bromobenzene. The bromobenzene in this reaction will be treated with both sulfuric and nitric acid. These two strong acids mix together to form a nitronium ion intermediate which is extremely electrophilic. The strong

mono-substituted aromatic compound, methyl m-nitrobenzoate, from methyl benzoate and a nitrating agent. conc. HNO3 C8H8O2 C8H7NO4 conc. H2SO4 Figure 1. Balanced-equation of methyl benzoate to methyl m-nitrobenzoate. Introduction In the presence of a good electrophile, an organic aromatic reactant in specific conditions is likely to undergo a chemical reaction, namely, electrophilic aromatic substitution. An electrophilic aromatic substitution involves the substitution of an unsaturated

For this lab we performed an electrophilic aromatic substitution through the nitration of methyl benzoate. Aromatic compounds can and do react with electrophiles under vigorous reaction conditions and in a presence of a catalyst. The stability of aromatic compounds is a result of resonance. Aromatic compounds only react with powerful electrophilic reagents and elevated temperatures because aromatic electrons are less reactive in addition reactions as formation of a carbocation intermediate entails

Introduction Electrophilic aromatic substitution (EAS) is an organic reaction in which an electrophilic reagent replaces a hydrogen attached to an aromatic ring. One of the most important type of EAS is halogenation, in this experiment, bromination of an aromatic compound. The main goal of this experiment is to investigate the activators in the aromatic system and how the substituent affect the activator’s efficacy through the products that have been obtained in the EAS reaction. The EAS reaction

2-chlorobutane. Tert-butyl-chloride would be expected to never react in a SN2 reaction, as it is so unreactive under these conditions. For each of the molecules used in this experiment (except tert-butyl-chloride), the nucleophile, iodine, would attack the electrophilic carbon bonded to the leaving group, chloride or bromide. That leaving group would then take the

Introduction:- In organic chemistry the substitution reactions is the most important reactions, especially Nucleophilic aromatic substitution reactions where nucleophile attacks positive charge or partially positive charge As it does so, it replaces a weaker nucleophile which then becomes a leaving group. The remaining positive or partially positive atom becomes an electrophile. The general form of the reaction is: Nuc: + R-LG → R-Nuc + LG: The electron pair (:) from the nucleophile (Nuc :) attacks

by performing a crystallization, vacuum filtration, and a recrystallization. Nitration is a commonly used reaction that involves an additional reaction that results in a resonance-stabilized intermediate that is later deprotonated to regenerate an aromatic ring. Because of methyl benzoate’s substituent, the nitro group is added in the meta position. The procedure included combining sulfuric acid, methyl benzoate, nitric acid, suction filtration, and purification through recrystallization. The recrystallized

Nucleophilic substitution reactions can be defined as reactions in which one nucleophile replaces another attached to a saturated carbon atom. A SN2 reaction occurs as a one step process also referred to as a second order due to its rate and is favored by 1°. For these reactions the intermediate is called pentavalent carbon because although there should never be more than four bonds on carbon, the nucleophile attacks as the same time the leaving group makes its way out causing the intermediate to

Introduction The goal of the experiment is to examine how the rate of reaction between Hydrochloric acid and Sodium thiosulphate is affected by altering the concentrations. The concentration of Sodium thiosulfate will be altered by adding deionised water and decreasing the amount of Sodium thiosulphate. Once the Sodium thiosulphate has been tested several times. The effect of concentration on the rate of reaction can be examined in this experiment. The chemical equation for this experiment is hydrochloric

2. In the contest of these two reactions, which is the better nucleophile, chloride ion or bromide ion? Try to explain this. Bromine is a better nucleophile. The chloride ion is more polar since it is above bromine on the periodic table and is more prone to hydrogen bonding due to its smaller size. Chloride ions are worse than bromine ions for nucleophilic attack, because the chloride ions are fully solvated and are not as available to attack. This is why Bromine ion is better nucleophile because

7) Discussion: The goal of this experiment was to covert 1-butanol into 1-bromobutane. By reacting 1-butanol with bromine, a nucleophilic substitution would occur where the alcohol group from 1-butanol is replaced with a bromine. In order for the -OH group to depart, its conjugate acid would have to be a strong acid. The conjugate acid for a hydroxyl group is water, which is a weak acid. To get the reaction to occur, 1-butanol would have to be reacted with sulfuric acid to protonate the -OH group

Double replacement reactions are fascinating. In this lab, 16 reactions are given to create a balanced chemical equation and predict products by using a solubility table. This experiment shows comprehension of reactions and provides reasoning and visuals into the complexities of double replacement reactions. The lab aims to enhance understanding of chemical reactions, providing some depth about these processes. A double replacement reaction is when two compounds exchange positive and negative ions

Introduction: The SN1 reaction is a substitution, nucleophilic, unimolecular reaction involving a two-step mechanism. The first step being the formation of a carbocation from the loss of a leaving group, the second being a rapid attack on the carbocation by the nucleophile. The term unimolecular can be used to describe this type of reaction since there is only one organic substance involved in the rate determining step. (3) Since the rate of the reaction is not dependent upon the nucleophile concentration

liquid chromatography and then prepared TLC plates to see which of the five vials collected contained the isolated product and an IR spectrum was then obtained. The reaction in this lab was an example of an SN2 reaction. SN2 is a nucleophilic substitution reaction where one bond is broken and one bond is formed in one step. For example, a lone pair from the oxygen in naphtholate anion attacks the carbon that is bonded to bromine from an allyl bromide molecule. This creates a partial C-O bond and

Introduction An unimolecular substitution reaction, SN1 reaction, has a two step mechanism that results in a halide group being displaced by a nucleophile1. In an SN1 reaction, the first step involves the leaving of a halide group to form a carbocation intermediate. This is the rate determining step, and it is also the slowest step. In the second step a nucleophile attacks a face of the the carbocation. Figure 1 displays this mechanism. Only one molecule, the substrate, determines the rate determining

There are two types of nucleophilic substitution: SN2 and SN1. The SN2 reaction mechanism is concerted meaning it involves only one step where the bonds of the leaving group and nucleophile are being formed and broken simultaneously1. The rate for this mechanism is dependent on both the concentration of the nucleophile and alkyl halide. The following figure displays the general mechanism for a SN2 reaction. The SN1 reaction mechanism is stepwise meaning that the leaving group departs first to

reader how to determine SN1 and SN2 reactions. Introduction: Substitution reactions are considered as SN1 or SN2 both consisting of nucleophiles. Substitution reactions that are SN2 consist of 2 reactants and two new products. In SN1 reactions consist of a unimolecular process. A nucleophile is electron rich which allows electrons to be donated to a carbon. An electrophile is an electron poor species that accepts electrons. Substitution reactions consist of an alkyl halide, or a substrate, or electrophile