Question 1

Which of the following statements best explains why aniline is less basic than methylamine?

Accepted Answer

Aniline's nitrogen lone pair is delocalized into the aromatic ring, reducing its availability for protonation.

Question 2

What is the product when R-norepinephrine reacts with HCl, and why is this transformation important in pharmaceutical formulations?

Accepted Answer

R-norepinephrine hydrochloride, which is water soluble and suitable for drug formulations.

Question 3

Which of the following amines is technically chiral but not resolvable due to rapid pyramidal inversion?

Accepted Answer

Amines with three different substituents on nitrogen, such as $$\mathrm{N(CH_3$)(C_2H_5)(C_3H_7)}$$

Question 4

Which reaction mechanism is responsible for the formation of methylamine from methyl bromide and ammonia?

Accepted Answer

An $$\mathrm{S_N2}$$ nucleophilic substitution mechanism

Question 5

Why can't the alkylation of ammonia with methyl bromide be stopped at the primary amine stage?

Accepted Answer

The primary amine formed is still nucleophilic and continues to react with methyl bromide, leading to secondary and tertiary amines.

Question 6

Which of the following heterocycles is aromatic and has a nitrogen lone pair that is part of the aromatic $$\pi$$ system, making it not basic?

Accepted Answer

Pyrrole

Question 7

What is the expected major product when a diazonium salt derived from aniline reacts with $$\mathrm{H_2O}$$?

Accepted Answer

Phenol ($$\mathrm{C_6H_5OH})$$

Question 8

Which statement best describes the selectivity of the azide reduction method for synthesizing amines?

Accepted Answer

It allows for the selective synthesis of primary amines from aryl halides.

Question 9

Which of the following statements about the pKa values of amines is correct?

Accepted Answer

A lower pKa value for the conjugate acid of an amine indicates the amine is less basic.

Question 10

Which of the following is true regarding the Hofmann elimination reaction?

Accepted Answer

It produces the less substituted alkene as the major product.

Question 11

What is the role of palladium in the Heck reaction?

Accepted Answer

It acts as a catalyst to facilitate oxidative addition, migratory insertion, and reductive elimination steps.

Question 12

Which of the following statements about cross-coupling reactions is correct?

Accepted Answer

They allow the formation of new C–C bonds under mild conditions, revolutionizing pharmaceutical synthesis.

Question 13

Which of the following is a correct general equation for alkene metathesis?

Accepted Answer

$$R_1CH=CH_2$ + R_2CH=CH_2$ \xrightarrow{	ext{catalyst}} R_1CH=$$CHR_2$$ + CH_2$=CH_2$

Question 14

Which of the following is true about the basicity of guanidine?

Accepted Answer

Guanidine is very basic, with a conjugate acid pKa of 13.6.

Question 15

Which of the following statements about the nitrosylation of secondary amines is correct?

Accepted Answer

It can produce carcinogenic nitrosamines, such as those formed when bacon is fried.

Question 16

Which of the following is a correct description of the mechanism for diazonium salt formation from a primary aromatic amine?

Accepted Answer

Reaction of $$R-NH_2$ with $$NaNO_2$$ and $$HCl$$ forms R$$-$$N_2^+Cl$$^-$$ via a nitrosation and dehydration sequence.

Question 17

Which of the following substituents on aniline will result in the lowest pKa for its conjugate acid?

Accepted Answer

A para-nitro group ($$p$$-$$NO_2)$$

Question 18

Which of the following is true about the Cope elimination reaction?

Accepted Answer

It is a syn stereoselective elimination that produces an alkene and a hydroxylamine.

Question 19

Which of the following is the correct nomenclature for the compound $$CH_3NHCH_2CH_3$$?

Accepted Answer

N-ethylmethylamine

Amines and Catalytic C–C Bond Formation: Structure, Properties, and Reactions

Guida di studio - Domande di pratica