Question 1

Provide the major organic product for the reaction. If you believe no product will be formed, explain why.

Accepted Answer

Sodium cyanoborohydride (NaBH₃CN) is a reagent used in reductive amination of an aldehyde or ketone. The amine will initially form an imine, and the imine will be reduced by the NaBH₃CN to give a secondary amine.

Sodium cyanoborohydride (NaBH<sub>3</sub>CN) is a reagent used in reductive amination of an aldehyde or ketone. The amine will initially form an imine, and the imine will be reduced by the NaBH<sub>3</sub>CN to give a secondary amine.

Question 2

Propose a structure for a compound with the molecular formula C5H11N that has the NMR spectra:
1H NMR F1F1F1S1F1F1F10 1.28 (s, 6H), 1.58 (s, 2H), 4.91 (dd, 1H), 5.20 (dd, 1H), 5.54 (dd, 1H) ppm
13C NMR F1F1F1S1F1F1F10 32.7, 52.7, 111.2, 145.4

Accepted Answer

First, calculate the degree of unsaturation from the molecular formula. Recall the formula: $$U = \frac { 2 C + 2 + N - H } { 2 }$$ Thus, the unsaturation number is equal to (2 × 5 + 2 + 1 - 11)/2 = 1, so there is one degree of unsaturation in the unknown compound. The ¹³C NMR data have peaks in the alkene region, so we can conclude the one degree is an alkene. The ¹H NMR data show three protons in the alkene region, so the compound is likely a monosubstituted alkene. The other major proton NMR peak is the singlet at 1.28 ppm integrating to six protons, indicating two identical methyl groups. The carbon bonded to the two methyl groups must also be bonded to the alkene, since this considers all five carbons from the molecular formula. This leaves us with NH₂ unaccounted for, so the structure must be:

Question 3

An unknown compound with the molecular formula C15H23N is treated with excess CH3I and heat, followed by Ag2O to give these two products. Deduce the structure of the unknown compound.

Accepted Answer

The conditions indicate a Hofmann elimination occurred. Recall that the first step of the Hofmann elimination is alkylation of an amine to form a good leaving group. In the second step, the Ag₂O acts as a base to drive an E2 elimination and form an alkene. Working backward, the amine must have been bonded to one of the alkene carbons, and the methyl group on the amine came from the CH₃I.

Note that option A has two possible beta hydrogens that can be removed. Elimination of the tertiary proton will give the products indicated, but the major product will be removal of the secondary proton, since it forms the less stable disubstituted alkene. Option B has only one possible beta hydrogen and the elimination will give the desired product. Therefore, option B must have been the unknown compound.

Question 4

Name the amine CH3CH2NHCH2CH3 using its common and IUPAC name, then classify the amine as primary, secondary, or tertiary.

Accepted Answer

The amine has the common name

Question 5

A student has produced the two isomers, A and B, and wants to use infrared (IR), 1H, and 13C NMR to distinguish between them. Identify what features in each spectroscopy method the student can quickly use to conclusively identify which isomer is which.

Accepted Answer

Both structures contain a hydroxy group

Question 6

Give the structure of the nucleophile that would react with CH3I to give triethylmethylphosphonium iodide. Show any unshared electron pairs and charges, where applicable.

Accepted Answer

A phosphonium salt is closely

Question 7

Predict the major organic product for the two reactions. If no reaction occurs, write NR and explain why.
​a. 
   ​
b.

Accepted Answer

a. Secondary amines react with

Question 8

An amine is considered a principal group for nomenclature in multifunctional compounds. How does it compare with the other principal groups?

Accepted Answer

A)  The amine has higher priority than a carboxylic acid. 
B)  The amine has higher priority than an aldehyde. 
C)  The amine has higher priority than an alcohol. 
D)  None of the other choices. 
A)  The amine has higher priority than a carboxylic acid. 
B)  The amine has higher priority than an aldehyde. 
C)  The amine has higher priority than an alcohol. 
D)  None of the other choices.

Question 9

Can this amine be resolved into enantiomers at room temperature? Explain why or why not.

Accepted Answer

No, although the amine has thr

Question 10

Identify the compound with the highest boiling point.

Accepted Answer

A)  CH3CH2CH2CH2NH2 
B)  CH3CH2CH2CH2OH 
C)  CH3CH2CH2CH2CH3 
D)  CH3CH2OCH2CH3 
A)  CH3CH2CH2CH2NH2 
B)  CH3CH2CH2CH2OH 
C)  CH3CH2CH2CH2CH3 
D)  CH3CH2OCH2CH3

Question 11

A student is hydrolyzing the amide below, and the reaction did not go to completion. The student wants to isolate just the neutral amine product. Design a separation and isolation method based on the basicities of all three compounds.

Accepted Answer

The amide hydrolysis occurs under acidic

Question 12

Name the amine using its common and IUPAC name, then classify the amine as primary, secondary, or tertiary.

Accepted Answer

The common name is N,N-dimethy

Question 13

Outline a synthesis of 1,3,5-trimethylbenzene from 2,4,6-trimethylaniline.

Accepted Answer

Looking at the product, the amine was re

Question 14

Cyclohexanecarbonyl chloride is converted to cyclohexanamine by this reaction. The major product formed in step 1 is an isocyanate. Draw the isocyanate and a curved-arrow mechanism showing how it is formed.

Accepted Answer

The reaction conditions demonstrate a Cu

Question 15

Determine the starting materials that could be used in two synthetic routes to make the amine by reductive amination.

Accepted Answer

There are two possible C-N bonds that co

Question 16

Draw a structure with the molecular formula C5H9N, which is a chiral primary amine with no triple bonds. (There is more than one correct answer.)

Accepted Answer

First, calculate the degree of unsaturat

Question 17

A student wants to make this amine using either the Gabriel synthesis or the Staudinger reaction. Will either method work? If so, deduce the structures of the starting materials. If not, explain why.

Accepted Answer

The Gabriel and Staudinger reactions are

Question 18

Predict the major organic product for the reaction. If you believe no reaction will occur, write NR and explain why.

Accepted Answer

The conditions shown are part of the Hof

Question 19

Aryldiazonium salts cannot be directly converted to

Accepted Answer

A)  Ph-X, where X is a halide. 
B)  Ph-CN. 
C)  Ph-OH. 
D)  Ph-CH3. 
A)  Ph-X, where X is a halide. 
B)  Ph-CN. 
C)  Ph-OH. 
D)  Ph-CH3.

Question 20

Deduce the structures of the aniline and phenol that are used to produce this azo dye.

Accepted Answer

Azo dyes are generated by the reaction o

Exam 23: The Chemistry of Amines

Provide the major organic product for the reaction. If you believe no product will be formed, explain why.

Propose a structure for a compound with the molecular formula C5H11N that has the NMR spectra: 1H NMR  1.28 (s, 6H), 1.58 (s, 2H), 4.91 (dd, 1H), 5.20 (dd, 1H), 5.54 (dd, 1H) ppm 13C NMR  32.7, 52.7, 111.2, 145.4

An unknown compound with the molecular formula C15H23N is treated with excess CH3I and heat, followed by Ag2O to give these two products. Deduce the structure of the unknown compound.

Name the amine CH3CH2NHCH2CH3 using its common and IUPAC name, then classify the amine as primary, secondary, or tertiary.

A student has produced the two isomers, A and B, and wants to use infrared (IR), 1H, and 13C NMR to distinguish between them. Identify what features in each spectroscopy method the student can quickly use to conclusively identify which isomer is which.

Give the structure of the nucleophile that would react with CH3I to give triethylmethylphosphonium iodide. Show any unshared electron pairs and charges, where applicable.

Predict the major organic product for the two reactions. If no reaction occurs, write NR and explain why. ​a. ​ b.

An amine is considered a principal group for nomenclature in multifunctional compounds. How does it compare with the other principal groups?

Can this amine be resolved into enantiomers at room temperature? Explain why or why not.

Identify the compound with the highest boiling point.

A student is hydrolyzing the amide below, and the reaction did not go to completion. The student wants to isolate just the neutral amine product. Design a separation and isolation method based on the basicities of all three compounds.

Name the amine using its common and IUPAC name, then classify the amine as primary, secondary, or tertiary.

Outline a synthesis of 1,3,5-trimethylbenzene from 2,4,6-trimethylaniline.

Cyclohexanecarbonyl chloride is converted to cyclohexanamine by this reaction. The major product formed in step 1 is an isocyanate. Draw the isocyanate and a curved-arrow mechanism showing how it is formed.

Determine the starting materials that could be used in two synthetic routes to make the amine by reductive amination.

Draw a structure with the molecular formula C5H9N, which is a chiral primary amine with no triple bonds. (There is more than one correct answer.)

A student wants to make this amine using either the Gabriel synthesis or the Staudinger reaction. Will either method work? If so, deduce the structures of the starting materials. If not, explain why.

Predict the major organic product for the reaction. If you believe no reaction will occur, write NR and explain why.

Aryldiazonium salts cannot be directly converted to

Deduce the structures of the aniline and phenol that are used to produce this azo dye.

Chemical Bonding and Chemical Structure

Alkanes and Organic Nomenclature

The Curved-Arrow Notation, Resonance, Acids and Bases, and Chemical Equilibrium

Introduction to Alkenes and Alkynes

Addition Reactions of Alkenes and Alkynes

Principles of Stereochemistry

Cyclic Compounds and Reaction Stereochemistry

Nomenclature and Noncovalent Intermolecular Interactions

The Chemistry of Alkyl Halides

Free-Radical Reactions, Main-Group Organometallic Compounds, and Carbenes

The Chemistry of Alcohols and Thiols

The Chemistry of Ethers, Epoxides, Glycols, and Sulfides

Introduction to Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Dienes and Aromaticity

The Chemistry of Benzene and Its Derivatives

Allylic and Benzylic Reactivity

The Chemistry of Aryl Halides, Vinylic Halides, and Phenols

The Chemistry of Aldehydes and Ketones

The Chemistry of Carboxylic Acids

The Chemistry of Carboxylic Acid Derivatives

The Chemistry of Enolate Ions, Enols, and Α,β-Unsaturated Carbonyl Compounds

Carbohydrates

The Chemistry of Thioesters, Phosphate Esters, and Phosphate Anhydrides

The Chemistry of the Aromatic Heterocycles and Nucleic Acids

Amino Acids, Peptides, and Proteins

Pericyclic Reactions

Filters

Propose a structure for a compound with the molecular formula C₅H₁₁N that has the NMR spectra: ¹H NMR  1.28 (s, 6H), 1.58 (s, 2H), 4.91 (dd, 1H), 5.20 (dd, 1H), 5.54 (dd, 1H) ppm ¹³C NMR  32.7, 52.7, 111.2, 145.4

An unknown compound with the molecular formula C₁₅H₂₃N is treated with excess CH₃I and heat, followed by Ag₂O to give these two products. Deduce the structure of the unknown compound.

Name the amine CH₃CH₂NHCH₂CH₃ using its common and IUPAC name, then classify the amine as primary, secondary, or tertiary.

A student has produced the two isomers, A and B, and wants to use infrared (IR), ¹H, and ¹³C NMR to distinguish between them. Identify what features in each spectroscopy method the student can quickly use to conclusively identify which isomer is which.

Give the structure of the nucleophile that would react with CH₃I to give triethylmethylphosphonium iodide. Show any unshared electron pairs and charges, where applicable.

Predict the major organic product for the two reactions. If no reaction occurs, write NR and explain why. a. b.

Draw a structure with the molecular formula C₅H₉N, which is a chiral primary amine with no triple bonds. (There is more than one correct answer.)