Substitution reactions Essays

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:- 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

Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above. 3. To purify and identify the product, recrystallization is used

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

Conducting Results from Various Substitution Reactions that Contain Alcohol Sophia Gruszczyk*, Riley Clark Department of Chemistry and Chemical Biology, IUPUI, 402 N. Blackford St., Indianapolis, IN 46202. segruszc@iu.edu The purpose of this experiment was to determine the structure of a specific product(s) from a given starting material. The reaction that was tested was that of substitution reactions, whether it was SN1 or SN2. Reaction 1 is an SN2 reaction because of the presence of a strong

concentrated nitric acid with concentrated sulfuric acid was to achieve Reaction 1 from Table 1, formation of the nitronium ion. Both of these reactions were kept at temperatures around 0°C, since they are exothermic reaction and presence of heat could lead to production of unnecessary dinitro by-products. The nitronium ion mixture was slowly added to the concentrated sulfuric acid methyl benzoate mixture to prevent vigorous reaction that if present could lead to unwanted dinitro by-products. The mixture

a transesterification reaction. In a transesterification reaction, the alkoxy part of the ester is exchanged for a different alkoxy group. Biodiesels are fuels that are produced from renewable plant or animal wastes. It is a mixture of methyl esters of long chain carboxylic acids that are produced from naturally occurring oils. For this experiment, vegetable oil will be used to synthesis biodiesel. The mechanism for this reaction is a nucleophilic acyl substitution reaction. In the synthesis, the

and then the relative rates of bromination for a set of arenes was 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

likely to undergo a chemical reaction, namely, electrophilic aromatic substitution. An electrophilic aromatic substitution involves the substitution of an unsaturated bond in an aromatic ring with an electrophile (E), to form an arenium ion or sigma complex (-C+-CEH-). Deprotonation at the arenium ion will result in the reformation of the unsaturated bond to preserve stability and the molecule's aromacity. This specific mechanism of electrophilic aromatic substitution is called arenium ion mechanism

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

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

The objective of this lab was to obtain a pure sample of methyl nitrobenzoate. This was done 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

Nucleophilic Substitution: Preparation of 1-Bromobutane & Alkyl Halide Classification Tests Reference: Experimental Organic Chemistry: A Miniscale and Microscale Approach 6th ed., by Gilbert and Martin, Chapter 10 and Chapter 14 Discussion: The purpose of this experiment is to look deeper into the nucleophilic substitution bi-molecular conversion of a primary alcohol, 1-butanol, into a primary bromoalkane, 1-bromobutane, using hydrobromic acid from the reaction between sodium bromide and concentrated

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. The leaving would then be a water, with a conjugate acid of hydronium (H3O+), which is a very strong acid. The reaction would then

inform the 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

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

In a two-day experiment, an SN2 reaction was conducted and benzyl bromide, sodium hydroxide, and an unknown were used. In a nucleophilic substitution reaction, the nucleophile and the alkyl carbon determine if the reaction is an SN2 or SN1 reaction. In an SN2 reaction, the process occurs in one step and works best with a primary carbon along with a strong nucleophile. During the experiment, recrystallization was used to purified the product; meanwhile, the melting point range and thin layer chromatography

Introduction SN2 stands for substitution, nucleophilic, bimolecular and occurs in one step where the nucleophile and electrophile react: the nucleophile attacks the electrophile 180° from the leaving group.3 The leaving group is nothing more than a group that leaves the electrophile attacked by the nucleophile. In this experiment the nucleophile is bromide, the electrophile is 1-butanol, and the leaving group is hydroxide. However, bromide must first be obtained from hydrobromic acid which gets bromide

Nucleophilic Substitution: Preparation of 1-Bromobutane and Alkyl Halide Classification Tests Introduction This procedure was undertaken in order to convert a primary alcohol, 1-butanol, into a primary alkyl halide, 1-bromobutane. This was done using hydrobromic acid. Additionally, tests were performed to assess the degree of the alkyl halide: primary, secondary or tertiary. These tests were the silver nitrate test and the sodium iodide test. The goal of these tests was to verify that 1-bromobutane

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