Chapter 23.7, Problem 19PTS

(a)

Interpretation Introduction

Interpretation: For a given compound set of compounds, the given amines are to be prepared via Gabriel synthesis, reductive amination starting from potassium phthalimide

Concept Introduction: Gabriel synthesis plays a very important role for preparing amines.  In this method, secondary and tertiary amines are not formed as side products.  It involves in three steps.

Step-1:  Formation of potassium phthalimide (deprotonation)

Potassium phthalimide in alkaline KOH acts as the reagent which has negatively charged phthalimide.  It is formed by the reaction between phthalimide and potassium hydroxide.

Step-2: Formation of R−N bond by S_N2 nucleophilic substitution

The negative charged nitrogen atom in phthalimide can easily attract the positive side of R−X.  In primary alkyl halides (R−X), R and X get positive and negative charges, respectively when they ionize.  As a result, a bond between nitrogen of phthalimide and carbon of R is formed.  This is S_N2 nucleophilic substitution reaction.  Halogen atom is going away as halide anion.

Step-3: Formation of primary amine by hydrolysis

The resultant product further goes for hydrolysis using hydrazine as the reagent.  This reaction also follows nucleophilic substitution reaction.  Finally, primary amine is formed with a side product of hydrazine derivative.

Sodium cyanoborohydride is a strong reducing agent than sodium borohydride.  It reduces the carbonyl group into amine group in a rapid way.  So, it is called as reductive amination reactions.  Aldehyde or ketone group is reacted with ammonia in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce primary amines.

Aldehyde or ketone group is reacted with primary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce secondary amines.

Aldehyde or ketone group is reacted with secondary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce tertiary amines.

(b)

Interpretation Introduction

Interpretation: For a given compound set of compounds, the given amines are to be prepared via Gabriel synthesis, reductive amination starting from potassium phthalimide

Concept Introduction: Gabriel synthesis plays a very important role for preparing amines.  In this method, secondary and tertiary amines are not formed as side products.  It involves in three steps.

Step-1:  Formation of potassium phthalimide (deprotonation)

Potassium phthalimide in alkaline KOH acts as the reagent which has negatively charged phthalimide.  It is formed by the reaction between phthalimide and potassium hydroxide.

Step-2: Formation of R−N bond by S_N2 nucleophilic substitution

The negative charged nitrogen atom in phthalimide can easily attract the positive side of R−X.  In primary alkyl halides (R−X), R and X get positive and negative charges, respectively when they ionize.  As a result, a bond between nitrogen of phthalimide and carbon of R is formed.  This is S_N2 nucleophilic substitution reaction.  Halogen atom is going away as halide anion.

Step-3: Formation of primary amine by hydrolysis

The resultant product further goes for hydrolysis using hydrazine as the reagent.  This reaction also follows nucleophilic substitution reaction.  Finally, primary amine is formed with a side product of hydrazine derivative.

Sodium cyanoborohydride is a strong reducing agent than sodium borohydride.  It reduces the carbonyl group into amine group in a rapid way.  So, it is called as reductive amination reactions.  Aldehyde or ketone group is reacted with ammonia in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce primary amines.

Aldehyde or ketone group is reacted with primary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce secondary amines.

Aldehyde or ketone group is reacted with secondary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce tertiary amines.

(c)

Interpretation Introduction

Interpretation: For a given compound set of compounds, the given amines are to be prepared via Gabriel synthesis, reductive amination starting from potassium phthalimide

Concept Introduction: Gabriel synthesis plays a very important role for preparing amines.  In this method, secondary and tertiary amines are not formed as side products.  It involves in three steps.

Step-1:  Formation of potassium phthalimide (deprotonation)

Potassium phthalimide in alkaline KOH acts as the reagent which has negatively charged phthalimide.  It is formed by the reaction between phthalimide and potassium hydroxide.

Step-2: Formation of R−N bond by S_N2 nucleophilic substitution

The negative charged nitrogen atom in phthalimide can easily attract the positive side of R−X.  In primary alkyl halides (R−X), R and X get positive and negative charges, respectively when they ionize.  As a result, a bond between nitrogen of phthalimide and carbon of R is formed.  This is S_N2 nucleophilic substitution reaction.  Halogen atom is going away as halide anion.

Step-3: Formation of primary amine by hydrolysis

The resultant product further goes for hydrolysis using hydrazine as the reagent.  This reaction also follows nucleophilic substitution reaction.  Finally, primary amine is formed with a side product of hydrazine derivative.

Sodium cyanoborohydride is a strong reducing agent than sodium borohydride.  It reduces the carbonyl group into amine group in a rapid way.  So, it is called as reductive amination reactions.  Aldehyde or ketone group is reacted with ammonia in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce primary amines.

Aldehyde or ketone group is reacted with primary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce secondary amines.

Aldehyde or ketone group is reacted with secondary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce tertiary amines.

(d)

Interpretation Introduction

Interpretation: For a given compound set of compounds, the given amines are to be prepared via Gabriel synthesis, reductive amination starting from potassium phthalimide

Concept Introduction: Gabriel synthesis plays a very important role for preparing amines.  In this method, secondary and tertiary amines are not formed as side products.  It involves in three steps.

Step-1:  Formation of potassium phthalimide (deprotonation)

Potassium phthalimide in alkaline KOH acts as the reagent which has negatively charged phthalimide.  It is formed by the reaction between phthalimide and potassium hydroxide.

Step-2: Formation of R−N bond by S_N2 nucleophilic substitution

The negative charged nitrogen atom in phthalimide can easily attract the positive side of R−X.  In primary alkyl halides (R−X), R and X get positive and negative charges, respectively when they ionize.  As a result, a bond between nitrogen of phthalimide and carbon of R is formed.  This is S_N2 nucleophilic substitution reaction.  Halogen atom is going away as halide anion.

Step-3: Formation of primary amine by hydrolysis

The resultant product further goes for hydrolysis using hydrazine as the reagent.  This reaction also follows nucleophilic substitution reaction.  Finally, primary amine is formed with a side product of hydrazine derivative.

Sodium cyanoborohydride is a strong reducing agent than sodium borohydride.  It reduces the carbonyl group into amine group in a rapid way.  So, it is called as reductive amination reactions.  Aldehyde or ketone group is reacted with ammonia in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce primary amines.

Aldehyde or ketone group is reacted with primary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce secondary amines.

Aldehyde or ketone group is reacted with secondary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce tertiary amines.

(e)

Interpretation Introduction

Interpretation: For a given compound set of compounds, the given amines are to be prepared via Gabriel synthesis, reductive amination starting from potassium phthalimide

Concept Introduction: Gabriel synthesis plays a very important role for preparing amines.  In this method, secondary and tertiary amines are not formed as side products.  It involves in three steps.

Step-1:  Formation of potassium phthalimide (deprotonation)

Potassium phthalimide in alkaline KOH acts as the reagent which has negatively charged phthalimide.  It is formed by the reaction between phthalimide and potassium hydroxide.

Step-2: Formation of R−N bond by S_N2 nucleophilic substitution

The negative charged nitrogen atom in phthalimide can easily attract the positive side of R−X.  In primary alkyl halides (R−X), R and X get positive and negative charges, respectively when they ionize.  As a result, a bond between nitrogen of phthalimide and carbon of R is formed.  This is S_N2 nucleophilic substitution reaction.  Halogen atom is going away as halide anion.

Step-3: Formation of primary amine by hydrolysis

The resultant product further goes for hydrolysis using hydrazine as the reagent.  This reaction also follows nucleophilic substitution reaction.  Finally, primary amine is formed with a side product of hydrazine derivative.

Sodium cyanoborohydride is a strong reducing agent than sodium borohydride.  It reduces the carbonyl group into amine group in a rapid way.  So, it is called as reductive amination reactions.  Aldehyde or ketone group is reacted with ammonia in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce primary amines.

Aldehyde or ketone group is reacted with primary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce secondary amines.

Aldehyde or ketone group is reacted with secondary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce tertiary amines.

(f)

Interpretation Introduction

Interpretation: For a given compound set of compounds, the given amines are to be prepared via Gabriel synthesis, reductive amination starting from potassium phthalimide

Concept Introduction: Gabriel synthesis plays a very important role for preparing amines.  In this method, secondary and tertiary amines are not formed as side products.  It involves in three steps.

Step-1:  Formation of potassium phthalimide (deprotonation)

Potassium phthalimide in alkaline KOH acts as the reagent which has negatively charged phthalimide.  It is formed by the reaction between phthalimide and potassium hydroxide.

Step-2: Formation of R−N bond by S_N2 nucleophilic substitution

The negative charged nitrogen atom in phthalimide can easily attract the positive side of R−X.  In primary alkyl halides (R−X), R and X get positive and negative charges, respectively when they ionize.  As a result, a bond between nitrogen of phthalimide and carbon of R is formed.  This is S_N2 nucleophilic substitution reaction.  Halogen atom is going away as halide anion.

Step-3: Formation of primary amine by hydrolysis

The resultant product further goes for hydrolysis using hydrazine as the reagent.  This reaction also follows nucleophilic substitution reaction.  Finally, primary amine is formed with a side product of hydrazine derivative.

Sodium cyanoborohydride is a strong reducing agent than sodium borohydride.  It reduces the carbonyl group into amine group in a rapid way.  So, it is called as reductive amination reactions.  Aldehyde or ketone group is reacted with ammonia in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce primary amines.

Aldehyde or ketone group is reacted with primary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce secondary amines.

Aldehyde or ketone group is reacted with secondary amine in the presence of sodium cyanoborohydride as a reducing agent and a proton source in the reaction medium to produce tertiary amines.