Textbook Question
What nucleophiles would form the following compounds as a result of reacting with 1-iodobutane?
g.
1152
views
Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 1)31
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 2)65
- Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry84
- Ch. 3 - An Introduction to Organic Compounds:Nomenclature, Physical Properties, and Structure183
- Ch. 4 - Isomers: The Arrangement of Atoms in Space121
- Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics83
- Ch. 6 - The Reactions of Alkenes • The Stereochemistry of Addition Reactions175
- Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis119
- Ch. 8 - Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene148
- Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides212
- Ch. 10 - Reactions of Alcohols, Ethers, Epoxides, Amines, and Sulfur-Containing Compounds131
- Ch. 11 - Organometallic Compounds60
- Ch. 12 - Radicals90
- Ch. 13 - Mass Spectrometry; Infrared Spectroscopy; UV/Vis Spectroscopy62
- Ch. 14 - NMR Spectroscopy95
- Ch. 15 - Reactions of Carboxylic Acids and Carboxylic Acid Derivatives123
- Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives141
- Ch. 17 - Reactions at the Alpha-Carbon101
- Ch. 18 - Reactions of Benzene and Substituted Benzenes144
- Ch. 19 - More About Amines • Reactions of Heterocyclic Compounds49
- Ch. 20 - The Organic Chemistry of Carbohydrates80
- Ch. 21 - Amino Acids, Peptides, and Proteins57
- Ch. 22 - Catalysis in Organic Reactions and in Enzymatic Reactions35
- Ch. 23 - The Organic Chemistry of the Coenzymes—Compounds Derived from Vitamins1
- Ch. 28 - Pericyclic Reactions58
All textbooks
Bruice 8th EditionCh. 9 - Substitution and Elimination Reactions of Alkyl HalidesProblem 71c,d
Bruice 8th EditionCh. 9 - Substitution and Elimination Reactions of Alkyl HalidesProblem 71c,dChapter 10, Problem 71c,d
Explain how each of the following changes affect the rate of the reaction of 1-bromobutane with ethoxide ion in DMF.
c. The alkyl halide is changed to 1-chlorobutane.
d. The alkyl halide is changed to 2-bromobutane.
Verified step by step guidance1
Step 1: Understand the reaction mechanism. The reaction of 1-bromobutane with ethoxide ion in DMF (dimethylformamide) is an example of an SN2 reaction. SN2 reactions are bimolecular nucleophilic substitution reactions where the rate depends on both the concentration of the nucleophile and the substrate.
Step 2: Analyze the effect of changing the alkyl halide to 1-chlorobutane. In SN2 reactions, the leaving group plays a critical role. Bromide (Br⁻) is a better leaving group than chloride (Cl⁻) because it is larger and more polarizable, making it more stable as a free ion. Replacing 1-bromobutane with 1-chlorobutane will decrease the reaction rate because chloride is a less effective leaving group.
Step 3: Analyze the effect of changing the alkyl halide to 2-bromobutane. The structure of the alkyl halide also affects the SN2 reaction rate. 1-bromobutane is a primary alkyl halide, while 2-bromobutane is a secondary alkyl halide. SN2 reactions proceed more readily with primary alkyl halides because there is less steric hindrance around the carbon undergoing substitution. Changing to 2-bromobutane will decrease the reaction rate due to increased steric hindrance.
Step 4: Consider the solvent's role. DMF is a polar aprotic solvent, which stabilizes the nucleophile (ethoxide ion) without stabilizing the leaving group. This makes it an ideal solvent for SN2 reactions. The solvent remains constant in this problem, so its effect does not change.
Step 5: Summarize the effects. Changing the alkyl halide to 1-chlorobutane decreases the reaction rate due to a poorer leaving group. Changing the alkyl halide to 2-bromobutane decreases the reaction rate due to increased steric hindrance around the reactive carbon.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Nucleophilicity
Nucleophilicity refers to the ability of a nucleophile to donate an electron pair to an electrophile, facilitating a chemical reaction. In the context of the reaction between 1-bromobutane and ethoxide ion, the strength of the nucleophile (ethoxide) and the leaving group (bromide or chloride) significantly influence the reaction rate. Generally, stronger nucleophiles and better leaving groups enhance the reaction rate.
Recommended video:
Guided course
08:27
Nucleophilic Addition
Leaving Group Ability
The leaving group ability is a critical factor in nucleophilic substitution reactions. A good leaving group can stabilize the negative charge after it departs, making the reaction more favorable. In this case, bromide is a better leaving group than chloride, which means that changing from 1-bromobutane to 1-chlorobutane would likely decrease the reaction rate due to the poorer leaving group.
Recommended video:
Guided course
03:06How to use the factors affecting acidity to predict leaving group ability.
Substitution Mechanism
The substitution mechanism, particularly whether the reaction follows an SN1 or SN2 pathway, affects the reaction rate. 1-bromobutane typically undergoes an SN2 reaction due to its primary carbon structure, while 2-bromobutane can undergo both SN1 and SN2 mechanisms. The steric hindrance in 2-bromobutane can slow down the SN2 pathway, potentially leading to a different rate of reaction compared to 1-bromobutane.
Recommended video:
Guided course
00:38Intro to Substitution/Elimination Problems
Related Practice
Textbook Question
What nucleophiles would form the following compounds as a result of reacting with 1-iodobutane?
h.
1154
views
Textbook Question
Starting with cyclohexene, how can the following compounds be prepared?
b. cyclohexylmethylamine
1390
views
Textbook Question
Explain how the following changes affect the rate of the reaction of 2-bromo-2-methylbutane with methanol:
a. The alkyl halide is changed to 2-chloro-2-methylbutane.
b. The alkyl halide is changed to 2-chloro-3-methylbutane.
1074
views
1
rank
Textbook Question
Starting with cyclohexene, how can the following compounds be prepared?
a. methoxycyclohexane
572
views
Textbook Question
Explain how each of the following changes affect the rate of the reaction of 1-bromobutane with ethoxide ion in DMF.
a. The concentration of both the alkyl halide and the nucleophile are tripled.
b. The solvent is changed to ethanol.
1100
views