Chapter 25, Problem 25.55P

Draw the organic products formed in each reaction.

a. f.

b. g.

c. h.

d. i.

e. j.

Interpretation Introduction

(a)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: The reaction between amine and alkyl halide is direct nucleophilic substitution reaction. The amino group acts as nucleophile and attacks the electrophilic carbon in alkyl halide followed by deprotonation to form amine or ammonium salt.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 1

Explanation of Solution

The reaction between ($2$-chloroethyl) cyclohexane and excess ammonia is shown below.

Figure 2

In the given reaction, the ammonia acts as nucleophile and attacks the carbon atom bonded to chlorine atom to produce the $2$-cyclohexylethanamine.

Conclusion

The organic product formed in the given reaction is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: Gabriel synthesis is a method of preparation of primary amines. This is a nucleophilic substitution reaction. The phthalimide in presence of base forms the resonance stabilized anion which acts as a nucleophile and attacks the electrophilic carbon of alkyl halides.

Answer to Problem 25.55P

The organic product formed in the given reaction is ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}{\text{CHCH}}_{\text{2}}{\text{NH}}_{\text{2}}$, $2$-methylpropan-$1$-amine.

Explanation of Solution

The reaction between $1$-chloro-$2$-methylpropane and pthalimide in presence of base is shown below.

Figure 3

In presence of base, phthalimide forms the resonance stabilized anion which acts as a nucleophile and attacks the electrophilic carbon of $1$-chloro-$2$-methylpropane to produce the $2$-methylpropan-$1$-amine.

Conclusion

The organic product formed in the given reaction is ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}{\text{CHCH}}_{\text{2}}{\text{NH}}_{\text{2}}$, $2$-methylpropan-$1$-amine.

Interpretation Introduction

(c)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: The synthesis of amine can be carried out by reduction of nitro compounds, nitriles and amides. Nitro compounds can be reduced to amines using catalytic hydrogenation or iron/palladium/tin metal in presence of acid. Nitriles and amides are reduced to amines using lithium aluminium hydride.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 4

Explanation of Solution

In the presence of tin metal with acid, $1$-bromo-$4$-nitrobenzene is reduced to $4$-nitroaniline. The corresponding reaction is shown below.

Figure 5

Conclusion

The organic product formed in the given reaction is shown in Figure 4.

Interpretation Introduction

(d)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: The synthesis of amine can be carried out by reduction of nitro compounds, nitriles and amides. Nitro compounds can be reduced to amines using catalytic hydrogenation or iron/palladium/tin metal in presence of acid. Nitriles and amides are reduced to amines using lithium aluminium hydride.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 6

Explanation of Solution

In the presence of lithium aluminium hydride, $2$-cyanobutane is reduced to $2$-methylbutan-$1$-amine. The corresponding reaction is shown below.

Figure 7

Conclusion

The organic product formed in the given reaction is shown in Figure 6.

Interpretation Introduction

(e)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: The synthesis of amine can be carried out by reduction of nitro compounds, nitriles and amides. Nitro compounds can be reduced to amines using catalytic hydrogenation or iron/palladium/tin metal in presence of acid. Nitriles and amides are reduced to amines using lithium aluminium hydride.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 8

Explanation of Solution

In the presence of lithium aluminium hydride, $N$-ethylcyclohexanecarboxamide is reduced to $N$-(cyclohexylmethyl) ethanamine. The corresponding reaction is shown below.

Figure 9

Conclusion

The organic product formed in the given reaction is shown in Figure 8.

Interpretation Introduction

(f)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: Amines reacts with acid chlorides or anhydrides to form amides. The amino group acts as nucleophile and attacks the carbonyl carbon of acid chlorides or anhydrides resulting in formation of amides and loss of chlorides or carboxylate ion.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 10

Explanation of Solution

The given amine, $2$-phenylethanamine reacts with benzoylbenzoate to form $N$-phenethylbenzamide. The corresponding reaction is shown below.

Figure 11

Conclusion

The organic product formed in the given reaction is shown in Figure 10.

Interpretation Introduction

(g)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: Sodium nitrite and hydrochloric acid reacts to form nitrous acid. Nitrous acid in presence of acid forms nitrosonium ion which reacts with primary amines to produce diazonium salt and with secondary amines produce $N$-nitrosamine.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 12

Explanation of Solution

Pyrrolidine reacts with nitrous acid to form $N$-nitrosamine. The corresponding reaction is shown below.

Figure 13

Conclusion

The organic product formed in the given reaction is shown in Figure 12.

Interpretation Introduction

(h)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: The conversion of aldehydes and ketones into amines is known as reductive amination. The first step is the formation of imines using aldehydes or ketones and amines. The second step involves the reduction of imine to form amine. The best reagent for this reaction is sodiumcyanoborohydride.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 14

Explanation of Solution

Pyrrolidine reacts with benzaldehyde to form imine. The imine undergoes reduction to form $1$-benzylpyrrolidine. The corresponding reaction is shown below.

Figure 15

Conclusion

The organic product formed in the given reaction is shown in Figure 14.

Interpretation Introduction

(i)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: Aldehyde or ketone on reaction with primary amine forms imine. Imine is also known as Schiff base. The nucleophilic attack of primary amine on carbonyl carbon results in the formation of intermediate carbinolamine. This intermediate loses water to form an imine.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 16

Explanation of Solution

Piperidine reacts with cyclohexanone to form imine. The corresponding reaction is shown below.

Figure 17

Conclusion

The organic product formed in the given reaction is shown in Figure 16.

Interpretation Introduction

(j)

Interpretation: The organic product formed in the given reaction is to be drawn.

Concept introduction: The conversion of amines into alkenes can be achieved by Hoffmann elimination reaction. Amines have poor leaving groups. They react with excess of alkyl halides to form ammonium salts. These ammonium salts undergo $\text{β}$-elimination reaction to form alkenes. The $\text{β}$-elimination refers to removal of proton from the $\text{β}$-carbon atom by the base.

Answer to Problem 25.55P

The organic product formed in the given reaction is,

Figure 18

Explanation of Solution

$N$-isopropylpropan-$1$-amine reacts with excess methyl iodide to form ammonium salt. This ammonium salt undergoes $\text{β}$-elimination to form propene. The corresponding reaction is shown below.

Figure 19

Conclusion

The organic product formed in the given reaction is shown in Figure 18.